Cisco IOS IP Routing: BGP Command Reference

clear bgp nsap

To clear and then reset Connectionless Network Service (CLNS) network service access point (NSAP) Border Gateway Protocol (BGP) sessions, use the clear bgp nsap command in privileged EXEC mode.

clear bgp nsap {* | as-number | ip-address} [soft] [in | out]

Syntax Description

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear bgp nsap command is similar to the clear ip bgp command, except that it is NSAP address family-specific.

Use of the clear bgp nsap command allows a reset of the neighbor sessions with varying degrees of severity, depending on the specified keywords and arguments.

Use the * keyword to reset all neighbor sessions. The software will clear and then reset the neighbor connections. Use this form of the command in the following situations:

•BGP timer specification change

•BGP administrative distance changes

Use the soft out keywords to clear and reset only the outbound neighbor connections. Inbound neighbor sessions will not be reset. Use this form of the command in the following situations:

•Additions or changes are made to the BGP-related access lists

•BGP-related weights change

•BGP-related distribution lists change

•BGP-related route maps change

Use the in keyword to clear only the inbound neighbor connections. Outbound neighbor sessions will not be reset. Use this form of the command in the following situations:

•BGP-related access lists change or get additions

•BGP-related weights change

•BGP-related distribution lists change

•BGP-related route maps change

Examples

In the following example, the inbound session with the neighbor 172.20.16.6 is cleared without the outbound session being reset:

Router# clear bgp nsap 172.20.16.6 in

In the following example, a soft clear is applied to outbound sessions with the neighbors in autonomous system 65000 without the inbound session being reset:

Router# clear bgp nsap 65000 soft out

Related Commands

clear bgp nsap dampening

To clear Border Gateway Protocol (BGP) route dampening information for the network service access point (NSAP) address family and unsuppress the suppressed routes, use the clear bgp nsap dampening command in privileged EXEC mode.

clear bgp nsap dampening [nsap-prefix]

Syntax Description

Command Default

When the nsap-prefix argument is not specified, the clear bgp nsap dampening command clears route dampening information for the entire BGP routing table for the NSAP address family.

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear bgp nsap dampening command is similar to the clear ip bgp dampening command, except that it is specific to the NSAP address family.

Examples

In the following example, route dampening information is cleared for the route to NSAP prefix 49.6001 and locally suppressed routes are unsuppressed:

Router# clear bgp nsap dampening 49.6001

Related Commands

clear bgp nsap external

To clear all external BGP (eBGP) peers for the network service access point (NSAP) address family, use the clear bgp nsap external command in privileged EXEC mode.

clear bgp nsap external [soft] [in | out]

Syntax Description

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear bgp nsap external command is similar to the clear ip bgp external command, except that it is specific to the NSAP address family.

Examples

In the following example, the inbound sessions with external BGP peers are cleared without the outbound sessions being reset:

Router# clear bgp nsap external soft in

Related Commands

clear bgp nsap flap-statistics

To clear Border Gateway Protocol (BGP) flap statistics for the network service access point (NSAP) address family, use the clear bgp nsap flap-statistics command in privileged EXEC mode.

clear bgp nsap flap-statistics [nsap-prefix] [regexp regexp | filter-list access-list-number]

Syntax Description

Command Default

No statistics are cleared.

If no arguments or keywords are specified, the software clears flap statistics for all routes.

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear bgp nsap flap-statistics command is similar to the clear ip bgp flap-statistics command, except that it is specific to the NSAP address family.

The flap statistics for a route are also cleared when an NSAP BGP peer is reset. Although the reset withdraws the route, no penalty is applied in this instance even though route flap dampening is enabled.

Examples

In the following example, all of the flap statistics for paths that pass access list 3 are cleared:

Router# clear bgp nsap flap-statistics filter-list 3

Related Commands

clear bgp nsap peer-group

To clear the Border Gateway Protocol (BGP) TCP connections to all members of a BGP peer group for the network service access point (NSAP) address family, use the clear bgp nsap peer-group command in privileged EXEC mode.

clear bgp nsap peer-group peer-group-name

Syntax Description

Command Default

No BGP TCP connections are cleared.

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear bgp nsap peer-group command is similar to the clear ip bgp peer-group command, except that it is specific to the NSAP address family.

Examples

In the following example, the BGP TCP connections are cleared for all members of the NSAP BGP peer group named internal:

Router# clear bgp nsap peer-group internal

Related Commands

clear ip bgp

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration, use the clear ip bgp command in privileged EXEC mode.

clear ip bgp {* | all | autonomous-system-number | neighbor-address | peer-group group-name} [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Note Due to the complexity of some of the keywords available for the clear ip bgp command, some of the keywords are documented as separate commands. All of the complex keywords that are documented separately start with clear ip bgp. For example, for information on resetting BGP connections using hard or soft reconfiguration for all BGP neighbors in IPv4 address family sessions, refer to the clear ip bgp ipv4 command.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound session with the neighbor 10.100.0.1, and the outbound session is unaffected:

Router# clear ip bgp 10.100.0.1 soft in

In the following example, the route refresh capability is enabled on the BGP neighbor routers and a soft reconfiguration is initiated for the inbound session with the neighbor 172.16.10.2, and the outbound session is unaffected:

Router# clear ip bgp 172.16.10.2 in

In the following example, a hard reset is initiated for sessions with all routers in the autonomous system numbered 35700:

Router# clear ip bgp 35700

In the following example, a hard reset is initiated for sessions with all routers in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.

Router# clear ip bgp 65538

In the following example, a hard reset is initiated for sessions with all routers in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.

Router# clear ip bgp 1.2

Related Commands

clear ip bgp dampening

To clear BGP route dampening information and to unsuppress suppressed routes, use the clear ip bgp dampening command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] dampening [network-address] [ipv4-mask]

Syntax With Address Family Syntax

clear ip bgp [ipv4 {multicast | unicast}] dampening [network-address] [ipv4-mask]

clear ip bgp [vrf vrf-name] [vpnv4 unicast] dampening [rd route-distinguisher] [network-address] [ipv4-mask]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp dampening is used to clear stored route dampening information. If no keywords or arguments are entered, route dampening information for the entire routing table is cleared.

Examples

The following example clears route dampening information for VPNv4 address family prefixes from network 192.168.10.0/24 and unsuppress suppressed routes.

Router# clear ip bgp vpnv4 unicast dampening 192.168.10.0 255.255.255.0 

Related Commands

clear ip bgp external

To reset external Border Gateway Protocol (eBGP) peering sessions using hard or soft reconfiguration, use the clear ip bgp external command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp external [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax With Address Family Syntax

clear ip bgp external [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax Description

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear ip bgp external command can be used to initiate a hard reset or soft reconfiguration of eBGP neighbor sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is configured for all inbound eBGP peering sessions:

Router# clear ip bgp external soft in 

In the following example, all outbound address family IPv4 multicast eBGP peering sessions are cleared:

Router# clear ip bgp external ipv4 multicast out

Related Commands

clear ip bgp flap-statistics

To clear BGP route dampening flap statistics, use the clear ip bgp flap-statistics command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] flap-statistics [neighbor-address [ipv4-mask] | regexp regexp | filter-list extcom-number]

Syntax With Address Family Syntax

clear ip bgp [neighbor-address] [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] flap-statistics

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp flap-statistics command is used to clear the accumulated penalty for routes that are received on a router that has BGP dampening enabled. If no arguments or keywords are specified, flap statistics are cleared for all routes. Flap statistics are also cleared when the peer is stable for the half-life time period.

Examples

In the following example, all of the flap statistics are cleared for paths that pass filter list 3:

Router# clear ip bgp flap-statistics filter-list 3 

In the following example, all of the flap statistics are cleared for the paths to the BGP neighbor at 10.2.1.3:

Router# clear ip bgp 10.2.1.3 flap-statistics

In the following example, all of the flap statistics are cleared for the paths to the BGP neighbor at 10.2.1.3 under IPv4 multicast address family:

Router# clear ip bgp 10.2.1.3 ipv4 multicast flap-statistics

Related Commands

clear ip bgp in prefix-filter

The in and prefix-filter keywords for the clear ip bgp command are no longer documented as a separate command.

The information for using the in and prefix-filter keywords with the clear ip bgp command has been incorporated into all the appropriate clear ip bgp command documentation. Due to the complexity of some of the keywords available for the clear ip bgp command, some of the keywords are documented as separate commands. All of the complex keywords that are documented separately start with clear ip bgp. For example, for information on resetting BGP connections using hard or soft reconfiguration for all BGP neighbors in IPv4 address family sessions, refer to the clear ip bgp ipv4 command.

clear ip bgp ipv4

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv4 address family sessions, use the clear ip bgp ipv4 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] ipv4 {multicast | mdt | unicast} autonomous-system-number [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp ipv4 command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically generating inbound updates) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for nondisruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp ipv4 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in IPv4 unicast address family sessions in autonomous system 65400, and the outbound session is unaffected:

Router# clear ip bgp ipv4 unicast 65400 soft in

In the following example, the route refresh capability is enabled on the IPv4 multicast address family BGP neighbors in autonomous system 65000, a soft reconfiguration is initiated for all inbound sessions with the IPv4 multicast address family neighbors, and the outbound session is unaffected:

Router# clear ip bgp ipv4 multicast 65000 in

In the following example, a hard reset is initiated for all BGP neighbor in IPv4 MDT address family sessions in the autonomous system numbered 65400:

Router# clear ip bgp ipv4 mdt 65400

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.

Router# clear ip bgp ipv4 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.

Router# clear ip bgp ipv4 unicast 1.2

Related Commands

clear ip bgp ipv6

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv6 address family sessions, use the clear ip bgp ipv6 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] ipv6 {multicast | unicast} autonomous-system-number [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp ipv6 command can be used to initiate a hard reset or soft reconfiguration of IPv6 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp ipv6 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in IPv6 unicast address family sessions, and the outbound session is unaffected:

Router# clear ip bgp ipv6 unicast soft in

In the following example, the route refresh capability is enabled on the IPv6 multicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the IPv6 multicast address family neighbors, and the outbound session is unaffected:

Router# clear ip bgp ipv6 multicast in

In the following example, a hard reset is initiated for neighbor sessions with all IPv6 unicast address family routers in the autonomous system numbered 35400:

Router# clear ip bgp ipv6 unicast 35400

In the following example, a hard reset is initiated for BGP neighbors in IPv6 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.

Router# clear ip bgp ipv6 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv6 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.

Router# clear ip bgp ipv6 unicast 1.2

Related Commands

clear ip bgp l2vpn

To reset Border Gateway Protocol (BGP) neighbor session information for Layer 2 Virtual Private Network (L2VPN) address family, use the clear ip bgp l2vpn command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] l2vpn vpls {autonomous-system-number | peer-group peer-group-name | update-group [number | ip-address]} [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Default

If no arguments or keywords are specified, all BGP L2VPN VPLS neighbor session information is cleared.

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp l2vpn command clears BGP session information for the L2VPN address family and VPLS SAFI. This command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use the clear ip bgp l2vpn command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp l2vpn vpls {autonomous-system-number | peer-group peer-group-name | update-group [number | ip-address]} in command. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After a soft reset (inbound or outbound) is configured, it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router memory pool.

Examples

The following example configures soft reconfiguration for the inbound session with BGP L2VPN peers in the 45000 autonomous system. The outbound session is unaffected:

Router# clear ip bgp l2vpn vpls 45000 soft in

Related Commands

clear ip bgp peer-group

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for all the members of a BGP peer group, use the clear ip bgp peer-group command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] peer-group peer-group-name [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax With Address Family Syntax

clear ip bgp [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] peer-group peer-group-name [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp peer-group command is used to initiate a hard reset or soft reconfiguration for neighbor sessions for BGP peer groups. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically generating inbound updates) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for nondisruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp peer-group command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, all members of the BGP peer group named INTERNAL are reset:

Router# clear ip bgp peer-group INTERNAL

In the following example, members of the peer group named EXTERNAL in IPv4 multicast address family sessions are reset:

Router# clear ip bgp ipv4 multicast peer-group EXTERNAL

In the following example, a soft reconfiguration is initiated for the inbound session with members of the peer group INTERNAL, and the outbound session is unaffected:

Router# clear ip bgp peer-group INTERNAL soft in

Related Commands

clear ip bgp table-map

To refresh table-map configuration information in the Border Gateway Protocol (BGP) routing table, use the clear ip bgp table-map command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] table-map

Syntax With Address Family Syntax

clear ip bgp [vrf vrf-name] [ipv4 {multicast | unicast} | vpnv4 unicast] table-map

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp table-map command is used to clear or refresh table-map configuration information in BGP routing tables. This command can be used to clear traffic-index information configured with the BGP Policy Accounting feature.

Examples

In the following example, a table map is configured and a traffic index is set. The new policy is applied after the clear ip bgp table-map command is entered.

Router(config)# route-map SET_BUCKET permit 10 

Router(config-route-map)# match community 1 

Router(config-route-map)# set traffic-index 2 

Router(config-route-map)# exit

Router(config)# router bgp 50000 

Router(config-router)# address-family ipv4 

Router(config-router-af)# table-map SET_BUCKET 

Router(config-router-af)# end

Router# clear ip bgp table-map

The following example clears the table map for IPv4 unicast peering sessions:

Router# clear ip bgp ipv4 unicast table-map

Related Commands

clear ip bgp update-group

To reset Border Gateway Protocol (BGP) connections for all the members of a BGP update group, use the clear ip bgp update-group command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] update-group [index-group | neighbor-address]

Syntax With Address Family Syntax

clear ip bgp [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] update-group [index-group | neighbor-address]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp update-group command is used to clear BGP update group member sessions. If no keywords or arguments are specified, entering this command will recalculate all update groups. Specific index numbers for update groups and information about update-group membership is displayed in the output of the show ip bgp update-group and debug ip bgp groups commands.

When a change to outbound policy occurs, the BGP routing process will automatically recalculate update-group memberships and apply changes by triggering an outbound soft reset after a 1-minute timer expires. This behavior is designed to provide the network operator with time to change the configuration before the soft reset is initiated. You can immediately initiate the outbound soft reset before the timer expires by entering the clear ip bgp ip-address soft out command or immediately initiate a hard reset by entering the clear ip bgp ip-address command.

Note In Cisco IOS Release 12.0(25)S, 12.3(2)T, and prior releases, the update group recalculation delay timer is set to 3 minutes.

Examples

In the following example, the membership of the 10.0.0.1 peer is cleared from an update group:

Router# clear ip bgp update-group 10.0.0.1 

In the following example, update-group information for all peers in the index 1 update group is cleared:

Router# clear ip bgp update-group 1 

In the following example, update-group information for all MDT address family session peers in the index 6 update group is cleared:

Router# clear ip bgp ipv4 mdt update-group 6 

Related Commands

clear ip bgp vpnv4

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv4 Virtual Private Network (VPNv4) address family sessions, use the clear ip bgp vpnv4 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] vpnv4 unicast autonomous-system-number [in [prefix-filter]] [out] [slow] [soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp vpnv4 command can be used to initiate a hard reset or soft reconfiguration of VPNv4 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp vpnv4 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in VPNv4 unicast address family sessions, and the outbound session is unaffected:

Router# clear ip bgp vpnv4 unicast soft in

In the following example, the route refresh capability is enabled on theVPNv4 unicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the VPNv4 multicast address family neighbors, and the outbound session is unaffected:

Router# clear ip bgp vpnv4 unicast in

In the following example, a hard reset is initiated for neighbor sessions with all VPNv4 unicast address family routers in the autonomous system numbered 35700:

Router# clear ip bgp vpnv4 unicast 35700

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.

Router# clear ip bgp vpnv4 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.

Router# clear ip bgp vpnv4 unicast 1.2

Related Commands

clear ip bgp vpnv4 unicast dampening

To reset Border Gateway Protocol (BGP) route flap dampening for a particular IPv4 Virtual Private Network version 4 (VPNv4) address family prefix, use the clear ip bgp vpnv4 unicast dampening command in privileged EXEC mode.

clear ip bgp vpnv4 unicast dampening rd route-distinguisher [network-address [network-mask]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

You can use the clear ip bgp vpnv4 unicast dampening command to clear stored route dampening information for the VPNv4 address family. If you specify a route-distinguisher in the command, the command clears all the prefixes that contain the particular route-distinguisher. If you specify a VPNv4 address in the command, the command clears the route dampening information for that particular network address.

Examples

The following example shows how to reset the flap dampening for a particular VPNv4 prefix:

Router# clear ip bgp vpnv4 unicast dampening rd 10:1 192.168.2.1 255.255.255.0

Related Commands

clear ip bgp vpnv6

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv6 Virtual Private Network (VPNv6) address family sessions, use the clear ip bgp vpnv6 command in privileged EXEC mode.

clear ip bgp vpnv6 unicast autonomous-system-number [in [prefix-filter]] [out] [slow]
[soft [in [prefix-filter] | out | slow]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

The clear ip bgp vpnv6 command can be used to initiate a hard reset or soft reconfiguration of VPNv6 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

•Additions or changes to the BGP-related access lists

•Changes to BGP-related weights

•Changes to BGP-related distribution lists

•Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:

Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp vpnv6 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in VPNv6 unicast address family sessions, and the outbound session is unaffected:

Router# clear ip bgp vpnv6 unicast soft in

In the following example, the route refresh capability is enabled on the VPNv6 unicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the IPv6 multicast address family neighbors, and the outbound session is unaffected:

Router# clear ip bgp vpnv6 unicast in

In the following example, a hard reset is initiated for neighbor sessions with all VPNv6 unicast address family routers in the autonomous system numbered 35700:

Router# clear ip bgp vpnv6 unicast 35700

In the following example, a hard reset is initiated for BGP neighbors in VPNv6 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.

Router# clear ip bgp vpnv6 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in VPNv6 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.

Router# clear ip bgp vpnv6 unicast 1.2

Related Commands

clear ip bgp vpnv6 unicast dampening

To reset Border Gateway Protocol (BGP) route flap dampening for a particular IPv6 Virtual Private Network version 6 (VPNv6) address family prefix, use the clear ip bgp vpnv6 unicast dampening command in privileged EXEC mode.

clear ip bgp vpnv6 unicast dampening [rd route-distinguisher [network-address]]

Syntax Description

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

You can use the clear ip bgp vpnv6 unicast dampening command to clear stored route dampening information for the VPNv6 address family. If you specify a route-distinguisher in the command, the command clears all the prefixes that contain the particular route-distinguisher. If you specify a VPNv6 address in the command, the command clears the route dampening information for that particular network address.

Examples

The following example shows how to reset the flap dampening for a particular VPNv6 prefix:

Router# clear ip bgp vpnv6 unicast dampening rd 1:0 2001:1000::0/64

Related Commands

clear ip prefix-list

To reset IP prefix-list counters, use the clear ip prefix-list command in privileged EXEC mode.

clear ip prefix-list [prefix-list-name] [network/length]

Syntax Description

Command Modes

Privileged EXEC

Command History

Usage Guidelines

The clear ip prefix-list command is used to clear prefix-list hit counters. The hit count is a value indicating the number of matches to a specific prefix list entry.

Examples

In the following example, the prefix-list counters are cleared for the prefix list named FIRST_LIST that matches the 10.0.0.0/8 prefix:

Router# clear ip prefix-list FIRST_LIST 10.0.0.0/8

Related Commands

continue

To configure a route map to go to a route-map entry with a higher sequence number, use the continue command in route-map configuration mode. To remove a continue clause from a route map, use the no form of this command.

continue [sequence-number]

no continue

Syntax Description

Defaults

If the sequence number argument is not configured when this command is entered, the continue clause will go to the route-map entry with the next default sequence number.

If a route-map entry contains a continue clause and no match clause, the continue clause will be executed automatically.

Command Modes

Route-map configuration (config-route-map)

Command History

Usage Guidelines

The continue command supports inbound route maps only in Cisco IOS Release 12.2(18)S and prior releases. Support for both inbound and outbound route maps was introduced in Cisco IOS Release 12.0(31)S and later releases.

Route Map Operation Without Continue Clauses

A route map evaluates match clauses until a successful match occurs. After the match occurs, the route map stops evaluating match clauses and starts executing set clauses, in the order in which they were configured. If a successful match does not occur, the route map "falls through" and evaluates the next sequence number of the route map until all configured route-map entries have been evaluated or a successful match occurs. Each route-map sequence is tagged with a sequence number to identify the entry. Route-map entries are evaluated in order starting with the lowest sequence number and ending with the highest sequence number. If the route map contains only set clauses, the set clauses will be executed automatically, and the route map will not evaluate any other route-map entries.

Route Map Operation With Continue Clauses

When a continue clause is configured, the route map will continue to evaluate and execute match clauses in the specified route-map entry after a successful match occurs. The continue clause can be configured to go to (or jump to) a specific route-map entry by specifying the sequence number, or if a sequence number is not specified, the continue clause will go to the next sequence number. This behavior is called an "implied continue." If a match clause exists, the continue clause is executed only if a match occurs. If no successful matches occur, the continue clause is ignored.

Match Operations With Continue Clauses

If a match clause does not exist in the route-map entry but a continue clause does, the continue clause will be automatically executed and go to the specified route-map entry. If a match clause exists in a route-map entry, the continue clause is executed only when a successful match occurs. When a successful match occurs and a continue clause exists, the route map executes the set clauses and then goes to the specified route-map entry. If the next route map contains a continue clause, the route map will execute the continue clause if a successful match occurs. If a continue clause does not exist in the next route map, the route map will be evaluated normally. If a continue clause exists in the next route map but a match does not occur, the route map will not continue and will "fall through" to the next sequence number if one exists.

Set Operations With Continue Clauses

Set clauses are saved during the match clause evaluation process and executed after the route-map evaluation is completed. The set clauses are evaluated and executed in the order in which they were configured. Set clauses are only executed after a successful match occurs, unless the route map does not contain a match clause. The continue statement proceeds to the specified route-map entry only after configured set actions are performed. If a set action occurs in the first route map and then the same set action occurs again, with a different value, in a subsequent route-map entry, the last set action will override any previous set actions that were configured with the same set command.

Note A continue clause can be executed, without a successful match, if a route-map entry does not contain a match clause.

Examples

In the following example, continue clause configuration is shown.

The first continue clause in route-map entry 10 indicates that the route map will go to route-map entry 30 if a successful matches occurs. If a match does not occur, the route map will "fall through" to route-map entry 20. If a successful match occurs in route-map entry 20, the set action will be executed and the route-map will not evaluate any additional route-map entries. Only the first successful match ip address clause is supported.

If a successful match does not occur in route-map entry 20, the route-map will "fall through" to route-map entry 30. This sequence does not contain a match clause, so the set clause will be automatically executed and the continue clause will go to the next route-map entry because a sequence number is not specified.

If there are no successful matches, the route-map will "fall through" to route-map entry 30 and execute the set clause. A sequence number is not specified for the continue clause so route-map entry 40 will be evaluated.

Router(config)# route-map ROUTE-MAP-NAME permit 10 

Router(config-route-map)# match ip address 1 

Router(config-route-map)# match metric 10 

Router(config-route-map)# set as-path prepend 10 

Router(config-route-map)# continue 30 

Router(config-route-map)# exit 

Router(config)# route-map ROUTE-MAP-NAME permit 20 

Router(config-route-map)# match ip address 2 

Router(config-route-map)# match metric 20 

Router(config-route-map)# set as-path prepend 10 10 

Router(config-route-map)# exit 

Router(config)# route-map ROUTE-MAP-NAME permit 30 

Router(config-route-map)# set as-path prepend 10 10 10 

Router(config-route-map)# continue 

Router(config-route-map)# exit 

Router(config)# route-map ROUTE-MAP-NAME permit 40

Router(config-route-map)# match community 10:1

Router(config-route-map)# set local-preference 104

Router(config-route-map)# exit 

Related Commands

debug ip bgp igp-metric ignore

To display information related to the system ignoring the Interior Gateway Protocol (IGP) metric during best path selection, use the debug ip bgp igp-metric ignore command in privileged EXEC mode. To disable such debugging output, use the no form of the command.

debug ip bgp igp-metric ignore

no debug ip bgp igp-metric ignore

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC (#)

Command History

Usage Guidelines

You might use this command if the path you expected to be chosen as the best path at the shadow RR was not chosen as such. That could be because the bgp bestpath igp-metric ignore command makes the best path algorithm choose the same best path as the primary RR if they are not co-located.

Examples

The following example turns on debugging of events related to the system ignoring the IGP metric during bestpath selection:

Router# debug ip bgp igp-metric ignore

Related Commands

debug ip bgp route-server

To turn on debugging for a BGP route server, use the debug ip bgp route-server command in privileged EXEC mode. To disable debugging output, use the no form of this command.

debug ip bgp route-server {client | context | event | import | policy} [detail]

no debug ip bgp route-server {client | context | event | import | policy} [detail]

Syntax Description

Command Modes

Privilaged EXEC (#)

Command History

Usage Guidelines

Use this command to turn on debugging of a BGP router server.

---

Caution The detail keyword is used for complex issues and should only be turned on when you are debugging with a Cisco representative.

---

Examples

In the following example, BGP route server client debugging is turned on:

Router# debug ip bgp route-server client

Related Commands

default-information originate (BGP)

To configure a Border Gateway Protocol (BGP) routing process to distribute a default route (network 0.0.0.0), use the default-information originate command in address family or router configuration mode. To disable the advertisement of a default route, use the no form of this command.

default-information originate

no default-information originate

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

Address family configuration
Router configuration

Command History

Usage Guidelines

The default-information originate command is used to configure a BGP routing process to advertise a default route (network 0.0.0.0). A redistribution statement must also be configured to complete this configuration or the default route will not be advertised.

The configuration of the default-information originate command in BGP is similar to the configuration of the network (BGP) command. The default-information originate command, however, requires explicit redistribution of the route 0.0.0.0. The network command requires only that the route 0.0.0.0 is present in the Interior Gateway Protocol (IGP) routing table. For this reason, the network command is preferred.

Note The default-information originate command should not be configured with the neighbor default-originate command on the same router. You should configure one or the other.

Examples

In the following example, the router is configured to redistribute a default route from OSPF into the BGP routing process:

Router(config)# router bgp 50000

Router(config-router)# address-family ipv4 unicast 

Router(config-router-af)# default-information originate 

Router(config-router-af)# redistribute ospf 100 

Router(config-router-af)# end 

Related Commands

default-metric (BGP)

To set a default metric for routes redistributed into Border Gateway Protocol (BGP), use the default-metric command in address family or router configuration mode. To remove the configured value and return BGP to default operation, use the no form of this command.

default-metric number

no default-metric number

Syntax Description

Defaults

The following is default behavior if this command is not configured or if the no form of this command is entered:

•The metric of redistributed interior gateway protocol (IGP) routes is set to a value that is equal to the interior BGP (iBGP) metric.

•The metric of redistributed connected and static routes is set to 0.

When this command is enabled, the metric for redistributed connected routes is set to 0.

Command Modes

Address family configuration
Router configuration

Command History

Usage Guidelines

The default-metric command is used to set the metric value for routes redistributed into BGP and can be applied to any external BGP (eBGP) routes received and subsequently advertised internally to iBGP peers.

This value is the Multi Exit Discriminator (MED) that is evaluated by BGP during the best path selection process. The MED is a non-transitive value that is processed only within the local autonomous system and adjacent autonomous systems. The default metric is not set if the received route has a MED value.

Note When enabled, the default-metric command applies a metric value of 0 to redistributed connected routes. The default-metric command does not override metric values that are applied with the redistribute command.

Examples

In the following example, a metric of 1024 is set for routes redistributed into BGP from OSPF:

Router(config)# router bgp 50000 

Router(config-router)# address-family ipv4 unicast 

Router(config-router-af)# default-metric 1024 

Router(config-router-af)# redistribute ospf 10 

Router(config-router-af)# end 

In the following configuration and output examples, a metric of 300 is set for eBGP routes received and advertised internally to an iBGP peer.

Router(config)# router bgp 65501

Router(config-router)# no synchronization

Router(config-router)# bgp log-neighbor-changes

Router(config-router)# network 172.16.1.0 mask 255.255.255.0

Router(config-router)# neighbor 172.16.1.1 remote-as 65501

Router(config-router)# neighbor 172.16.1.1 soft-reconfiguration inbound

Router(config-router)# neighbor 192.168.2.2 remote-as 65502

Router(config-router)# neighbor 192.168.2.2 soft-reconfiguration inbound

Router(config-router)# default-metric 300

Router(config-router)# no auto-summary

After the above configuration, some routes are received from the eBGP peer at 192.168.2.2 as shown 
in the output from the show ip bgp neighbors received-routes command.

Router# show ip bgp neighbors 192.168.2.2 received-routes 

BGP table version is 7, local router ID is 192.168.2.1 

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

              r RIB-failure, S Stale

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

*> 172.17.1.0/24    192.168.2.2                            0 65502 i

After the received routes from the eBGP peer at 192.168.2.2 are advertised internally to iBGP peers, 
the output from the show ip bgp neighbors received-routes command shows that the metric (MED) 
has been set to 300 for these routes.

Router# show ip bgp neighbors 172.16.1.2 received-routes

BGP table version is 2, local router ID is 172.16.1.1 

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

              r RIB-failure, S Stale

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

* i172.16.1.0/24    172.16.1.2               0    100      0 i

* i172.17.1.0/24    192.168.2.2            300    100      0 65502 i

Total number of prefixes 2

Related Commands

description (route server context)

To specify a description for a BGP route server context, use the description command in route server context configuration mode. To remove the description, use the no form of this command.

description string

no description

Syntax Description

Command Default

No description for a route server context exists.

Command Modes

Route server context configuration (config-router-rsctx)

Command History

Usage Guidelines

Create a route server context if you want your BGP route server to support customized, flexible policies. The routes needing flexible policy handling are selected for import into a route server context by an import map that you configure. The import map references a route map, where the actual policy is defined.

The description command allows an optional description of a route server context to remind you of the purpose of the context or policy, for example. This is more user-friendly and scannable than trying to interpret the route map commands when looking at a configuration file or show output.

Examples

In the following example, the description is a user-friendly way to see the purpose of the context, without having to interpret the import map and route map:

Router(config)# router bgp 65000

Router(config-router)# route-server-context only_AS27_context

Router(config-router-rsctx)# description Context references route map permitting only 
routes with AS 27 in AS path.

Related Commands

distance bgp

To configure the administrative distance for BGP routes, use the distance bgp command in address family or router configuration mode. To return to the administrative distance to the default value, use the no form of this command.

distance bgp external-distance internal-distance local-distance

no distance bgp

Syntax Description

Defaults

The following values are used if this command is not configured or if the no form is entered:

external-distance: 20
internal-distance: 200
local-distance: 200

Routes with a distance of 255 are not installed in the routing table.

Command Modes

Address family configuration
Router configuration

Command History

Usage Guidelines

The distance bgp command is used to configure a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is a positive integer from 1 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored. Use this command if another protocol is known to be able to provide a better route to a node than was actually learned via external BGP (eBGP), or if some internal routes should be preferred by BGP.

Caution Changing the administrative distance of internal BGP routes is considered dangerous and is not recommended. Improper configuration can introduce routing table inconsistencies and break routing.

The distance bgp command replaces the distance mbgp command.

Examples

In the following example, the external distance is set to 10, the internal distance is set to 50, and the local distance is set to 100:

Router(config)# router bgp 50000 

Router(config-router)# address family ipv4 multicast 

Router(config-router-af)# network 10.108.0.0 

Router(config-router-af)# neighbor 192.168.6.6 remote-as 123 

Router(config-router-af)# neighbor 172.16.1.1 remote-as 47 

Router(config-router-af)# distance bgp 10 50 100 

Router(config-router-af)# end 

Related Commands

distribute-list in (BGP)

To filter routes or networks received in incoming Border Gateway Protocol (BGP) updates, use the distribute-list in command in router configuration mode. To delete the distribute list and remove it from the running configuration file, use the no form of this command.

distribute-list {acl-number | prefix list-name} in

no distribute-list {acl-number | prefix list-name} in

Syntax Description

Defaults

If this command is configured without a predefined access list or prefix list, the distribute list will default to permitting all traffic.

Command Modes

Router configuration

Command History

Usage Guidelines

The distribute-list in command is used to filter incoming BGP updates. An access list or prefix list must be defined prior to configuration of this command. Standard and expanded access lists are supported. IP prefix lists are used to filter based on the bit length of the prefix. An entire network, subnet, supernet, or single host route can be specified. Prefix list and access list configuration is mutually exclusive when configuring a distribute list. The session must be reset with the clear ip bgp command before the distribute list will take effect.

Note Interface type and number arguments may be displayed in the CLI depending on the version of Cisco IOS software you are using. However, the interface arguments are not supported in any Cisco IOS software release.

Note We recommend that you use IP prefix lists (configured with the ip prefix-list command in global configuration mode) instead of distribute lists. IP prefix lists provide improved performance and are simpler to configure. Distribute list configuration will be removed from the CLI at a future date.

To suppress networks from being advertised in updates, use the distribute-list out command.

Examples

In the following example, a prefix list and distribute list are defined to configure the BGP routing process to accept traffic from only network 10.1.1.0/24, network 192.168.1.0, and network 10.108.0.0. An inbound route refresh is initiated to activate the distribute-list.

Router(config)# ip prefix-list RED permit 10.1.1.0/24

Router(config)# ip prefix-1ist RED permit 10.108.0.0/16 

Router(config)# ip prefix-list RED permit 192.168.1.0/24 

Router(config)# router bgp 50000 

Router(config-router)# network 10.108.0.0 

Router(config-router)# distribute-list prefix RED in 

Router(config-router)# end 

Router# clear ip bgp in 

In the following example, an access list and distribute list are defined to configure the BGP routing process to accept traffic from only network 192.168.1.0 and network 10.108.0.0. An inbound route refresh is initiated to activate the distribute-list.

Router(config)# access-list 1 permit 192.168.1.0 

Router(config)# access-list 1 permit 10.108.0.0 

Router(config)# router bgp 50000 

Router(config-router)# network 10.108.0.0 

Router(config-router)# distribute-list 1 in 

Router(config-router)# end 

Router# clear ip bgp in 

Related Commands

distribute-list out (BGP)

To suppress networks from being advertised in outbound Border Gateway Protocol (BGP) updates, use the distribute-list out command in router configuration mode. To delete the distribute list and remove it from the running configuration file, use the no form of this command.

distribute-list {acl-number | prefix list-name} out [protocol process-number | connected | static]

no distribute-list {acl-number | prefix list-name} out [protocol process-number | connected | static]

Syntax Description

Defaults

If this command is configured without a predefined access list or prefix list, the distribute list will default to permitting all traffic.

Command Modes

Router configuration

Command History

Usage Guidelines

The distribute-list out command is used to filter outbound BGP updates. An access list or prefix list must be defined prior to configuration of this command. Standard and expanded access lists are supported. IP prefix lists are used to filter based on the bit length of the prefix. An entire network, subnet, supernet, or single host route can be specified. Prefix list and access list configuration is mutually exclusive when configuring a distribute list. The session must be reset with the clear ip bgp command before the distribute list will take effect.

Note Interface type and number arguments may be displayed in the CLI depending on the version of Cisco IOS software you are using. However, the interface arguments are not supported in any Cisco IOS software release.

Note We recommend that you use IP prefix lists (configured with the ip prefix-list command in global configuration mode) instead of distribute lists. IP prefix lists provide improved performance and are simpler to configure. Distribute list configuration will be removed from the CLI at a future date.

Entering a protocol and/or process-number arguments causes the distribute list to be applied to only routes derived from the specified routing process. Addresses not specified in the distribute-list command will not be advertised in outgoing routing updates after a distribute list is configured.

To suppress networks or routes from being received in inbound updates, use the distribute-list in command.

Examples

In the following example, a prefix list and distribute list are defined to configure the BGP routing process to advertise only network 192.168.0.0. An outbound route refresh is initiated to activate the distribute-list.

Router(config)# ip prefix-list BLUE permit 192.168.0.0/16 

Router(config)# router bgp 50000 

Router(config-router)# distribute-list prefix BLUE out 

Router(config-router)# end 

Router# clear ip bgp out 

In the following example, an access list and a distribute list are defined to configure the BGP routing process to advertise only network 192.168.0.0. An outbound route refresh is initiated to activate the distribute-list.

Router(config)# access-list 1 permit 192.168.0.0 0.0.255.255 

Router(config)# access-list 1 deny 0.0.0.0 255.255.255.255 

Router(config)# router bgp 50000 

Router(config-router)# distribute-list 1 out 

Router(config-router)# end 

Router# clear ip bgp out 

Related Commands

exit-peer-policy

To exit policy-template configuration mode and enter router configuration mode, use the exit-peer-policy command in policy-template configuration mode.

exit-peer-policy

Syntax Description

This command has no keywords or arguments.

Command Default

No default behavior or values

Command Modes

Policy-template configuration

Command History

Examples

In the following example, the router is configured to exit policy-template configuration mode and enter router configuration mode:

Router(config-router-ptmp)# exit-peer-policy 

Router(config-router)#

Related Commands

exit-peer-session

To exit session-template configuration mode and enter router configuration mode, use the exit-peer-session command in session-template configuration mode.

exit-peer-session

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

Session-template configuration

Command History

Examples

In the following example, the router is configured to exit session-template configuration mode and enter router configuration mode:

Router(config-router-stmp)# exit-peer-session

Router(config-router)#

Related Commands