Global Interface Commands

This module describes the global command line interface (CLI) commands for configuring interfaces on the Cisco 8000 Series Routers.

To use commands of this module, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using any command, contact your AAA administrator for assistance.

bandwidth (global)

To configure the bandwidth of an interface, use the bandwidth command in interface configuration mode.

bandwidth rate

Syntax Description

rate

Amount of bandwidth to be allocated on the interface, in Kilobits per second (kbps). Range is from 0 through 4294967295.

Command Default

The default bandwidth depends on the interface type.

Command Modes

Interface configuration

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines


Note

To obtain the default bandwidth for a specific interface, use the show interfaces command after you first bring up the interface. The default interface bandwidth is displayed in the show interfaces command output.

Task ID

Task ID

Operations

interface

execute

basic-services

read, write

Examples

This example shows how to configure the bandwidth on a Ten Gigabit Ethernet interface: 


RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router# interface  TenGigE 0/4/1/0
RP/0/RP0/CPU0:router# bandwidth 4000000

cef load-balancing fields user-data

To specify the additional fields that are to be included in the hashing algorithm, which is used for load balancing during forwarding, use the cef load-balancing fields user-data command in XR Config mode. To undo a configuration, use the no form of this command.

cef load-balancing fields user-data { ipv4 | | ipv6 } { non-tcp-udp | | tcp | | udp } offset offset-value size size location { location | | WORD }

Syntax Description

user-data

Considers user data for hashing.

ipv4

Considers IPv4 header for hashing.

ipv6

Considers IPv6 header for hashing.

non-tcp-udp

Considers the additional data for non-tcp-udp packet for hashing.

tcp

Considers the additional data for TCP packet for hashing.

udp

Considers the additional data for UDP packet for hashing.

offset

Considers the payload based on the offset from the end of the chosen header for hashing.

offset-value

Specifies the value of the offset from the end of the header. This value ranges as follows:

  • ipv4 non-tcp-udp: 0-43 bytes

  • ipv4 tcp: 0-23 bytes

  • ipv4 udp: 0-35 bytes

  • ipv6 non-tcp-dup: 0-23 bytes

  • ipv6 tcp: 0-3 bytes

  • ipv6 udp: 0-15 bytes

size

Considers the size of the payload for hashing.

size

Considers the specified number of contiguous payload bytes from the offset-value for hashing. This value can range from 1-4.

location

Considers the ingress card location.

location

Specifies the ingress card location.

WORD

Specifies the ingress card location.

Command Default

By default, user-data fields are not considered for ECMP hashing.

Command Modes

XR Config mode

Command History

Release

Modification

Release 24.2.11

This command was introduced.

Usage Guidelines

  • The configuration is effective immediately with minimum load balance hashing impact.

  • By default, ECMP hashing algorithm uses fixed fields:

    • L4 protocol TCP or UDP, not fragmented: source IP address, destination IP address, L4 protocol, source port, destination port

    • Non TCP, non UDP, or TCP/UDP fragmented: source IP address, destination IP address, L4 protocol


      Note

      For IPv6 flows, in addition to these fields, 20-bit ipv6 flow-label is also used for hashing.

Task ID

Task ID Operation

cef

read, write

config-services

read, write

Examples

The following example shows how to specify the additional IPv4 header fields with offset, size, and location for ECMP path calculation:

In this example, the first four bytes of payload of any non-tcp-udp packet are additionally included in the hashing algorithm.


Router#configure
Router(config)#cef load-balancing fields user-data ipv4 non-tcp-udp offset 0 size 4 location 0/0/CPU0
Router(config)#commit

  • offset 0: The payload considered for hashing starts from the end of IP header

  • size 4: Four bytes of payload are considered.

clear interface

To clear interface statistics or packet counters, use the clear interface command in XR EXEC mode .

clear interface type interface-path-id

Syntax Description

type

Interface type. For more information, use the question mark (? ) online help function.

interface-path-id

Physical interface or virtual interface.

Note

 

Use the show interfaces command to see a list of all interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (? ) online help function.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Task ID

Task ID

Operations

interface

execute

basic-services

read, write

Examples

This example shows how to use the clear interface command to clear the loopback interface 2: 


RP/0/RP0/CPU0:router# clear interface loopback 2

dampening

To limit propagation of transient or frequently changing interface states on Interface Manager (IM) clients, turn on event dampening by using the dampening command in interface configuration mode. To turn dampening off, use the no form of this command.

dampening [half-life [reuse suppress max-suppress-time]]

Syntax Description

half-life

(Optional) Time (in minutes) after which a penalty is decreased. Once the interface has been assigned a penalty, the penalty is decreased by half after the half-life period. The process of reducing the penalty happens every 5 seconds. The range of the half-life period is 1 to 45 minutes. The default is 1 minute.

reuse

(Optional) Penalty value below which a stable interface is unsuppressed. Range is from 1 through 20000. Default value is 750.

suppress

(Optional) Limit at which an interface is suppressed when its penalty exceeds that limit. Range is from 1 through 20000, and must be greater than the reuse threshold. The default value is 2000.

max-suppress-time

(Optional) Maximum time (in minutes) that an interface can be suppressed. This value effectively acts as a ceiling that the penalty value cannot exceed. Default value is four times the half-life period.

Command Default

Dampening is turned off by default. When you use the dampening command, the following default values are enabled for any optional parameters that you do not enter:

  • half-life: 1 minute
  • reuse: 750
  • suppress: 2000
  • max-suppress-time: Four times the half-life

Command Modes

Interface configuration

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines

Event dampening suppresses a constantly unstable interface until it remains stable for a period of time. Enabling dampening on an interface that already has dampening configured has the effect of resetting the penalty associated with that interface to zero. The reuse threshold must always be less than the suppress threshold.

Consider the following guidelines when configuring event dampening:

  • Configuring dampening on both a subinterface and its parent is usually unnecessary because their states are almost always the same and dampening would be triggered at the same time on each interface.
  • If all subinterfaces require dampening, then apply dampening to the main interface only. Applying configuration to large numbers of subinterfaces requires an abundance of memory and increases the time required to process the configuration during boot and failover.
  • When dampening is enabled, an interface has a penalty value associated with it. The value starts at 0 and is increased by 1000 whenever the underlying state of the interface changes from up to down.
  • The penalty value decreases exponentially while the interface state is stable. If the penalty value exceeds a configured suppress threshold, then the state of the interface is suppressed and IM will not notify upper layers of further state transitions. The suppressed state remains until the penalty value decreases past a configured reuse threshold.

Task ID

Task ID

Operations

interface

read, write

Examples

This example shows how to enable dampening with default values on an interface: 


RP/0/RP0/CPU0:router(config)# interface TenGigE 0/4/0/0
RP/0/RP0/CPU0:router(config-if))# dampening

Related Commands

Command Description

show im dampening

Displays the state of all interfaces on which dampening has been configured.  

encapsulation dot1ad dot1q

To define the matching criteria to be used in order to map single-tagged 802.1ad frames ingress on an interface to the appropriate service instance, use the encapsulation dot1ad dot1q command in sub-interface configuration mode. To remove the configuration, use the no form of this command.

encapsulation dot1ad vlan-id dot1q vlan-id

Syntax Description

dot1ad

Indicates that the IEEE 802.1ad provider bridges encapsulation type is used for the outer tag.

dot1q

Indicates that the IEEE 802.1q standard encapsulation type is used for the inner tag.

vlan-id

VLAN ID, can be given as single ID.

Command Default

No matching criteria are defined.

Command Modes

Sub-interface configuration

Command History

Release

Modification

Release 7.2.12

This command was introduced.

Usage Guidelines

The outer VLAN tag is an 802.1ad VLAN tag, instead of an 802.1Q tag. An 802.1ad tag has an ethertype value of 0x88A8, instead of 0x8100 that 802.1Q uses.

Some of the fields in the 802.1ad VLAN header are interpreted differently per 802.1ad standard.

A tunneling ethertype command applied to the main interface does not apply to an 802.1ad sub-interface. An interface with encapsulation dot1ad causes the router to categorize the interface as an 802.1ad interface. This causes special processing for certain protocols and other features:

  • MSTP uses the IEEE 802.1ad MAC STP address instead of the STP MAC address.

  • Certain QoS functions may use the Drop Eligibility (DE) bit of the IEEE 802.1ad tag.

Examples

The following example shows how to map single-tagged 802.1ad ingress frames to a service instance: 


Router# configure
Router# interface hundredGigE 0/0/0/1.10
Router(config-subif)# encapsulation dot1ad 100 dot1q 20

Related Commands

Command Description

rewrite ingress tag

 Specifies the encapsulation adjustment that is to be performed on the frame ingress to the service instance.  

encapsulation dot1q

To define the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance, use the encapsulation dot1q command in the sub-interface configuration mode. To delete the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance, use the no form of this command.

encapsulation dot1q vlan-id

Syntax Description

vlan-id

VLAN ID, can be given as single ID.

Command Default

No matching criteria are defined.

Command Modes

Sub-interface configuration

Command History

Release

Modification

Release 7.2.12

This command was introduced.

Usage Guidelines

Only one encapsulation statement can be applied to a sub-interface. Encapsulation statements cannot be applied to main interfaces.

A single encapsulation dot1q statement specifies matching for frames with a single VLAN ID.

Examples

The following example shows how to map 802.1Q frames ingress on an interface to the appropriate service instance: 

Router# configure
Router(config)#interface HundredGigE 0/0/0/24.10 
Router(config-if)# encapsulation dot1q 10
The following example shows how to map 802.1Q frames ingress on an l2transport sub-interface: 

Router# configure
Router(config)# interface HundredGigE 0/0/0/24.10 l2transport
Router(config-subif)# encapsulation dot1q 10

Related Commands

Command Description

rewrite ingress tag

 Specifies the encapsulation adjustment that is to be performed on the frame ingress to the service instance.  

interface (global)

To configure an interface or to create or configure a virtual interface, use the interface command in XR Config mode. To delete the interface configuration, use the no form of this command.

interface type interface-path-id

Syntax Description

type

Interface type. For more information, use the question mark (? ) online help function.

interface-path-id

Physical interface or virtual interface.

Note

 

Use the show interfaces command to see a list of all interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (? ) online help function.

Command Default

No interfaces are configured

Command Modes

XR Config

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines

The interface command enters interface configuration mode to allow you to configure interfaces. If a virtual interface is configured, then the interface is created if it did not already exist.

The no form of this command applies only to virtual interfaces or to subinterfaces (that is, interfaces that have been created in global configuration mode).

Until Release 6.5.1, when you create an interface with some configurations, upon router or interface reload, interface configurations are lost. From Release 6.5.1, onwards, automatic shutdown config behavior is persistent and no shutdown configs are lost on interface or router reload.

Task ID

Task ID

Operations

interface

read, write

Examples

In the following example, the interface command is given for the card in location 0/2/0/1, and interface configuration mode is entered for that interface: 


RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/1

Related Commands

Command Description

clear interface

Clears interface statistics or packet counters.  

lacp system

To set the default system parameters for the Link Aggregation Control Protocol (LACP) bundles, use the lacp system command in XR Config mode .

lacp system{ mac| priority}

Syntax Description

mac

Unique MAC address used to identify the system in LACP negotiations.
priority

Priority for this system. Lower value is higher priority. Range is from 1 to 65535.

Command Default

System priority is 32768. MAC address is automatically assigned from the backplane pool.

Command Modes

XR Config

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines

The parameters are the system MAC address and the priority of the system. The MAC address must be unique to the system (if it matches a partner system, LACP negotiations fail). The combination of the MAC address and the set system priority determine the priority of the LACP bundles.

Task ID

Task ID Operation
bundle

read, write

Examples

The following example shows how to configure the MAC address on an LACP system:

RP/0/RP0/CPU0:router(config)lacp system mac 000c.15c0.bd15

mtu

To adjust the maximum transmission unit (MTU) value for packets on the interface, use the mtu command in interface configuration mode. To return the interface to the default MTU for the interface type, use the no form of this command.

mtu bytes

Syntax Description

bytes

Maximum number of bytes in a Layer 2 frame. Range is from 64 through 65535.

Command Default

The default MTU for each interface is as follows:

  • Ethernet—1514 bytes
  • POS—4474 bytes
  • Tunnel—1500 bytes
  • Loopback—1514 bytes
  • ATM—4470 bytes

Command Modes

Interface configuration

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines

Use the mtu command to set a specific MTU value for an interface, or use the no mtu command to return the interface to the default MTU value for that interface type. The MTU value can be increased or decreased using the mtu command, subject to minimum and maximum MTU limits for the interface type.

If the MTU value is not configured, then each interface will have a default MTU value that is specific to the interface type. The default MTU value is generally the largest Layer 2 frame size possible for the interface type.

The default/configured MTU value on an atm interface includes the L2 header.

The MTU size consists of L2 header that includes either SNAP(8bytes)/MUX(0)/NLPID(2) header or the AAL5 SDU. The AAL5 SDU includes the L3 datagram and the optional Logical Link Control/Subnetwork Access Protocol (LLC/SNAP) header.

The Ethernet interface is the Layer 3 datagram plus 14 bytes. For ATM main interface, the MTU is L3 datagram + 0 bytes.

For ATM L3 sub interface, mtu is as follows:

  • SNAP - L3 datagram + 8 bytes
  • NLPID - L3 datagram + 2 bytes
  • MUX - L3datagram + 0 bytes
  • When no pvc is configured under sub interface - L3datagram + 0 bytes

You can use the show interfaces command to determine if the MTU value has been changed. The show interfaces command output displays the MTU size for each interface in the MTU (byte) field. Note that the MTU size that is displayed includes the Layer 2 header bytes used for each encapsulation type.


Note

You can use the show interfaces command to determine if the MTU value has been changed. The show interfaces command output displays the MTU size for each interface in the MTU (byte) field. Note that the MTU size that is displayed includes the Layer 2 header bytes used for each encapsulation type.


Note

Changing the MTU on an interface triggers a change on the protocols and encapsulations configured on that interface, although some protocol-specific configurations can override the interface MTU. For example, specifically changing the interface MTU configuration does not affect the IP MTU configuration, but may affect the resulting MTU on that node.


Note

For the 10x10GigE CPAK (10 ports with only 8 profiles), it is not possible to support 10 different MTUs on 10 different 10GigE ports. One of the profiles needs to be reserved for the default MTU, in case you need to change the configured MTU back to the default MTU. Therefore on the 10x10g CPAK, you can configure different MTU sizes on 7 ports and the other 3 ports have the default MTU size. If you configure the 8th port, the configuration command succeeds but an error appears on the console.

Task ID

Task ID

Operations

interface

read, write

Examples

In this example, the MTU value for all interfaces is verified. The MTU value is shown in the next-to-last column: 


RP/0/RP0/CPU0:router# show interfaces all brief

                Intf        Intf         LineP              Encap  MTU       BW
                Name        State        State               Type (byte)   (Kbps)
--------------------------------------------------------------------------------
                 Nu0           up           up               Null  1500   Unknown
           TenGigE6/0/0/0      up           up               HDLC  4474   2488320
           TenGigE6/0/0/1      up           up               HDLC  4474   2488320
           TenGigE6/0/0/2   admin-down   admin-down          HDLC  4474   2488320
           TenGigE6/0/0/3   admin-down   admin-down          HDLC  4474   2488320
         Mg0//CPU0/0           up           up               ARPA  1514    100000

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface TenGigE 6/0/0/0
RP/0/RP0/CPU0:router(config-if)# mtu 1000

After the mtu command is used to decrease the MTU Layer 2 frame size for the POS interface on 6/0/0/0 to 1000 bytes, the show interfaces all brief command is used again to verify that the MTU Layer 2 frame size has been changed: 


RP/0/RP0/CPU0:router# show interfaces all brief 

                Intf        Intf         LineP              Encap  MTU       BW
                Name        State        State               Type (byte)   (Kbps)
--------------------------------------------------------------------------------
                 Nu0           up           up               Null  1500   Unknown
           PO6/0/0/0           up           up               HDLC  1000   2488320
           PO6/0/0/1           up           up               HDLC  4474   2488320
           PO6/0/0/2   admin-down   admin-down               HDLC  4474   2488320
           PO6/0/0/3   admin-down   admin-down               HDLC  4474   2488320
 Mg0//CPU0/0           up           up               ARPA  1514    100000

replace

To substitute any configuration in the router with new settings, use the replace command in XR Config mode.

replace interface interface_name_before with interface_name_after

replace pattern string_before with string_after [ dry-run ]

Syntax Description

interface

Specifies the details of interface configuration replacement follows.

interface_name_before

Specifies the name of an interface in the router that you want to replace.

For more information about the syntax for the router, use the question mark (? ) online help function.

interface_name_after

Specifies the new interface name that replaces the current interface name specified in the interface_name_before variable.

For more information about the syntax for the router, use the question mark (? ) online help function.

pattern

Specifies that the details of string replacement follow.

string_before

Specify the configuration string in the router that you need to replace. The string_before can be any regular expression that specifies a match pattern in text.

Note

 

You must specify the string_before in a single quote.

string_after

Specify the new string that replaces the configuration matching the string_before variable.

Note

 

You must specify the string_after in a single quote.

dry-run

Displays the configuration after the pattern replacement without preparing the config changes for a commit. This option facilitates verifying the pattern replacement changes and provides an extra layer of protection to avoid accidentally committing unwanted configuration changes.

Command Default

No default behavior or values.

Command Modes

XR Config

Command History

Release

Modification

Release 7.1.0

This command was introduced.

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID

Task ID

Operations

interface

read, write

Examples

The following example shows how to use the replace command: 


Router# config
Router(config)# replace interface gigabitEthernet 0/0/0/0 with loopback 450
Loading.
4 bytes parsed in 1 sec (3)bytes/sec 
   

Router# config
Router(config)# replace pattern '10\.20\.30\.40' with '100.200.250.225‘
Loading.
232 bytes parsed in 1 sec (230)bytes/sec

Examples

The following example details configuration changes on using the replace command:

Original Configuration:


Router(config-ospf-ar-if)#show configuration
Building configuration...
!! IOS XR Configuration 0.0.0
interface GigabitEthernet0/0/0/0
 description first
 ipv4 address 10.20.30.40 255.255.0.0
 shutdown
!
router ospf 10
 cost 100
 area 200
  cost 200
  interface GigabitEthernet0/0/0/0
   transmit-delay 5
  !

Using replace command: 

Router(config-ospf-ar-if)# replace interface gigabitEthernet 0/0/0/0 with loopback 450           
Building configuration...
Loading.
232 bytes parsed in 1 sec (230)bytes/sec

Configuration changes on using replace command: 


Router(config-ospf-ar-if)#show configuration
Building configuration...
!! IOS XR Configuration 0.0.0
interface Loopback450
 description first
 ipv4 address 10.20.30.40 255.255.0.0
 shutdown
!
no interface GigabitEthernet0/0/0/0
router ospf 10
 area 200
  interface Loopback450
   transmit-delay 5
  !
  no interface GigabitEthernet0/0/0/0

Examples

The following example shows how to use the dry-run option in the replace command: 


Router# config
Router(config)# replace pattern 'vrf thr' with 'vrf three' dry-run
no vrf thr
vrf three
 address-family ipv4 unicast
  import route-target
   65321:3
  !
  export route-target
   65321:3
  !
 !
exit
router static
 no vrf thr
 vrf three
  address-family ipv4 unicast
   192.168.3.0/24 vrf one 192.168.1.1
   192.168.3.0/24 vrf two 192.168.2.2
  !
exit
end
Router(config)# commit
No configuration changes to commit.

rewrite ingress tag

To specify the encapsulation adjustment that is to be performed on the frame ingress to the service instance, use the rewrite ingress tag command in the interface configuration mode. To delete the encapsulation adjustment that is to be performed on the frame ingress to the service instance, use the no form of this command.

rewrite ingress tag pop { 1 | 2 } symmetric | { push dot1ad vlan-id dot1q vlan-id | dot1q vlan-id symmetric } | { translate { 1-to-1 dot1ad vlan-id | dot1q vlan-id symmetric } | 1-to-2 dot1ad vlan-id dot1q vlan-id symmetric | 2-to-1 { dot1ad vlan-id | dot1q vlan-id } symmetric | 2-to-2 dot1ad vlan-id dot1q vlan-id symmetric }

Syntax Description

vlan-id

VLAN ID, can be given as single ID.

push dot1q vlan-id

Pushes one 802.1Q tag with vlan-id .

push dot1ad vlan-id

Pushes one Dot1ad tag with vlan-id .

pop 1

One tag is removed from the packet. This command can be combined with a push (pop N and subsequent push vlan-id ).

pop 2

Two tags are removed from the packet. This command can be combined with a push (pop N and subsequent push vlan-id ).

translate 1-to-1 dot1q vlan-id

or

translate 1-to-1 dot1ad vlan-id

Replaces the incoming tag (defined in the encapsulation command) into a different 802.1Q or dot1ad tag at the ingress service instance.

translate 1-to-2 dot1q vlan-id

or

translate 1-to-2 dot1ad vlan-id

Replaces the incoming tag defined by the encapsulation command by a pair of 802.1Q or dot1ad tags.

translate 2-to-2 dot1q vlan-id

or

translate 2-to-2 dot1ad vlan-id

Replaces the pair of tags defined by the encapsulation command by a pair of VLANs defined by this rewrite.

translate 2-to-1 dot1q vlan-id

or

translate 2-to-1 dot1ad vlan-id

Replaces a pair of tags defined in the encapsulation command by vlan-id.

symmetric

A rewrite operation is applied on both ingress and egress. The operation on egress is the inverse operation as ingress.

Note

 
Symmetric is the default behavior. Hence, it cannot be disabled.

Command Default

The frame is left intact on ingress.

Command Modes

Interface configuration

Command History

Release

Modification

Release 7.2.12

This command was introduced.

Usage Guidelines

The symmetric keyword is accepted only when a single VLAN is configured in encapsulation. If a list of VLANs is configured in encapsulation, the symmetric keyword is accepted only for push rewrite operations; all other rewrite operations are rejected.

The pop command assumes the elements being popped are defined by the encapsulation type.

The rewrite ingress tag translate command assume the tags being translated from are defined by the encapsulation type. In the 2-to-1 option, the “2” means 2 tags of a type defined by the encapsulation command. The translation operation requires at least “from” tag in the original packet. If the original packet contains more tags than the ones defined in the “from”, then the operation should be done beginning on the outer tag.

Examples

The following example shows how to specify the encapsulation adjustment that is to be performed on the frame ingress to the service instance: 


Router# configure
Router(config)# interface hundredGigE 0/0/0/24.1 l2transport
Router(config-if)# encapsulation dot1q 10
Router(config-if)# rewrite ingress tag push dot1q 200 symmetric

The following example shows how to remove one outer tag from the packet:


Router# configure
Router(config)# interface hundredGigE 0/0/0/24.1 l2transport
Router(config-if)# encapsulation dot1q 10
Router(config-subif)# rewrite ingress tag pop 1 symmetric

The following example shows how to replace the incoming tag (defined in the encapsulation command) into a different dot1ad tag at the ingress service instance: 


Router# configure
Router(config)# interface hundredGigE 0/0/0/24.1 l2transport
Router(config-if)# encapsulation dot1q 10
Router(config-subif)# rewrite ingress tag translate 1-to-1 dot1ad 2 symmetric

Related Commands

Command Description

encapsulation dot1q

Defines the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance.  

encapsulation dot1ad dot1q

 Defines the matching criteria to be used in order to map single-tagged 802.1ad frames ingress on an interface to the appropriate service instance.  

show im dampening

To display the state of all interfaces on which dampening has been configured, use the show im dampening command in XR EXEC mode .

show im dampening [interface type | ifhandle handle]

Syntax Description

interface type

(Optional) Interface type. For more information, use the question mark (? ) online help function.

ifhandle handle

(Optional) Identifies the caps node whose Interface Manager (IM) dampening information you want to display.

Command Default

If you do not specify an interface, then the system displays brief details about all dampened interfaces.

Command Modes

EXEC

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Usage Guidelines

If you do not specify an interface, then the system displays brief details about all dampened interfaces.

The physical hardware (layer 1) is not the only part of an interface that can change state. L2 keepalive failure event is one of the many instances that can have a similar impact on routing protocols despite the underlying interface state staying UP. To take account of such events, when dampening is configured on an interface, it is applied independently to every layer. They all use the same parameters as the interface but they have their own penalty value which is incremented when that layer changes state.

Capsulations that may be dampened in this way include these:

  • L2 basecaps, such as HDLC and PPP, which may flap if keepalives are not received due to events such as intermittent packet loss.

  • L3 capsulations (for example ipv4, ipv6). These may be brought down if another link has a conflicting IP address configured.

  • Other locations where negotiation takes place with a peer router, as in the case of PPP control protocols such as IPCP. If the negotiation fails, then the caps is brought down.

Task ID

Task ID

Operations

interface

read

Examples

This example shows the output from the show im dampening command issued with default values: 


RP/0/RP0/CPU0:router(config)# interface TenGigE 0/4/0/0
RP/0/RP0/CPU0:router(config-if)# no shutdown
RP/0/RP0/CPU0:router(config-if)# dampening
RP/0/RP0/CPU0:router# show im dampening

Interface               Proto              Caps               Penalty Suppressed

---------               -----              ----               ----------------
TenGigE0/4/0/0              0                  0                  0       NO

RP/0/RP0/CPU0:router# show im dampening interface TenGigE 0/4/0/0 

TenGigE0/4/0/0 (0x05000d00)
Dampening enabled: penalty 0, not suppressed
  underlying state: Up
  half_life: 1        reuse:             750
  suppress:  3000     max-suppress-time: 4
  restart-penalty:   0

RP/0/RP0/CPU0:router# show interfaces TenGigE 0/4/0/0 

TenGigE0/4/0/0 is up, line protocol is down
  Dampening enabled: penalty 0, not suppressed
    half_life: 1        reuse:             750
    suppress:  3000     max-suppress-time: 4
    restart-penalty:  0
  Hardware is Ten Gigabit Ethernet
  Description: ensoft-gsr5 TenGigE 4\2
  Internet address is Unknown
  MTU 4474 bytes, BW 155520 Kbit
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation HDLC, crc 16, controller loopback not set, keepalive set (10 sec)
  Last clearing of "show interface" counters never
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 total input drops
     0 drops for unrecognized upper-level protocol
     Received 0 broadcast packets, 0 multicast packets
              0 runts, 0 giants, 0 throttles, 0 parity
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     48 packets output, 1504 bytes, 0 total output drops
     Output 0 broadcast packets, 0 multicast packets
     0 output errors, 0 underruns, 0 applique, 0 resets
     0 output buffer failures, 0 output buffers swapped out

This sample output shows a POS interface with PPP basecaps and IPCP. The subsequent output for show im dampening interface <ifname> contains a table of any capsulations which have their own penalty as shown below: 



RP/0/RP0/CPU0:router# show im dampening

Interface                   Protocol           Capsulation          Pen   Sup
--------------------------- ------------------ -------------------- ----- ---
HundredGigabitEthernet0/0/0/0                                       629   NO 
HundredGigabitEthernet0/0/0/1                                       2389  YES
POS0/2/0/0                                                          0     NO 
POS0/2/0/0                  <base>             ppp                  0     NO 
POS0/2/0/0                  ipv4               ipcp                 0     NO 

   
RP/0/RP0/CPU0:router# show im dampening interface TenGigaE 0/1/0/0 

TenGigE 0/1/0/0 (0x01180020)
Dampening enabled: Penalty 1625, SUPPRESSED (42 secs remaining)
  Underlying state: Down
  half-life: 1        reuse:             1000     
  suppress:  1500     max-suppress-time: 4 
  restart-penalty:  0

Protocol       Capsulation        Pen   Suppression              U-L State  
-------------- ------------------ ----- --------------------- -------------
 ipv6           ipv6               1625  YES    42s  remaining        Down

Note

When dampening is configured on an interface it is also applied independently to all capsulations on that interface. For example, the ppp or hdlc basecaps state can flap even while the interface stays up and if keepalives fail. The show im dampening interface command contains one line for each such capsulation as well as the interface itself.

Table 1. show im dampening Field Descriptions

Field

Description

Dampening

Indicates the dampening state and penalty value: not suppressed, suppressed.

underlying state

Underlying state of the interface: up, down, administratively down (if an interface has been configured to be “shutdown”).

half_life

This is the time (in minutes) at which the penalty on the interface would be half that of the original penalty (of 1000) when the interface transitions from UP to DOWN. It ranges from 1 to 45 minutes and the default is 1 minute.

reuse

Penalty value below which a stable interface is unsuppressed. It ranges from 1 to 20000 and the default value is 750.

suppress

Limit at which an unstable interface is suppressed when the penalty value exceeds the suppress value. It ranges from 1 to 20000 and the default value is 2000.

max-suppress-time

Maximum time (in minutes) that an interface can be suppressed. The default is 4 minutes.

restart-penalty

Penalty assigned to the interface when it flaps.

Related Commands

Command Description

dampening

Turns on event dampening.  

show interfaces

To display statistics for all interfaces configured on the router or for a specific node, use the show interfaces command in XR EXEC mode.

show interfaces [ type interface-path-id | all | local | location node-id ] [ accounting | brief | description | detail | summary | counters rate physical ]

Syntax Description

type

(Optional) Specifies the type of interface for which you want to display statistics. For more information, use the question mark (? ) online help function.

interface-path-id

Physical interface or virtual interface.

Note

 

Use the show interfaces command to see a list of all interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (? ) online help function.

all

(Optional) Displays interface information for all interfaces. This is the default.

local

(Optional) Displays interface information for all interfaces in the local card.

location node-id

(Optional) Displays information about all interfaces on the specified node. The node-id argument is entered in the rack/slot/module notation.

accounting

(Optional) Displays the number of packets of each protocol type that have been sent through the interface.

brief

(Optional) Displays brief information of each interface (one line per interface).

description

(Optional) Displays the status, protocol, and description of each interface (one line per interface).

detail

(Optional) Displays detailed information about each interface. This is the default.

summary

(Optional) Displays a summary of interface information by interface type.

counters rate physical

(Optional) Displays the ingress and egress statistics of all physical interfaces.

The following details are displayed: InterfaceName, Intval, InMbps, InBW%, InKpps, OutMbps, OutBW%, OutKpps.

Note

 

This keyword is applicable only for Cisco 8000 platform.

Command Default

No default behavior or values

Command Modes

XR EXEC mode

Command History

Release

Modification

Release 7.0.12

This command was introduced.

Release 7.9.1

New keyword "counters" was added for Cisco 8000 platform.

Usage Guidelines

The show interfaces command displays statistics for the network interfaces. The resulting display shows the interface processors in slot order.

For example, if you type the show interfaces command without an interface type, you receive information for all the interfaces installed in the networking device. Only by specifying the interface type , slot , and port arguments can you display information for a particular interface.

If you enter a show interfaces command for an interface type that has been removed from the networking device, an error message is displayed: “Interface not found.”

The output displayed depends on the network for which an interface has been configured.


Note

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average is within 2 percent of the instantaneous rate of a uniform stream of traffic over that period.

Task ID

Task ID

Operations

interface

read

Examples

This example shows the output from the show interfaces command. The output displayed depends on the type and number of interface cards in the networking device. 


RP/0/RP0/CPU0:router# show interfaces HundredGigE 0/3/0/35 

HundredGigE0/3/0/35 is up, line protocol is up
  Interface state transitions: 1
  Hardware is HundredGigE, address is e666.9aa0.223c (bia e666.9aa0.223c)
  Description: **To RouterX Hu0/7/0/2**
  Internet address is 192.168.1.29/30
  MTU 1514 bytes, BW 100000000 Kbit (Max: 100000000 Kbit)
     reliability 255/255, txload 239/255, rxload 238/255
  Encapsulation ARPA,
  Full-duplex, 100000Mb/s, unknown, link type is force-up
  output flow control is off, input flow control is off
  Carrier delay (up) is 10 msec
  loopback not set,
  Last link flapped 3w3d
  ARP type ARPA, ARP timeout 04:00:00
  Last input 00:00:00, output 00:00:00
  Last clearing of "show interface" counters never
  30 second input rate 93725392000 bits/sec, 32528692 packets/sec
  30 second output rate 93726416000 bits/sec, 32527860 packets/sec
     68118736643563 packets input, 24783244282360579 bytes, 0 total input drops
     0 drops for unrecognized upper-level protocol
     Received 0 broadcast packets, 0 multicast packets
              0 runts, 0 giants, 0 throttles, 0 parity
     174 input errors, 174 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     68115867305777 packets output, 24782409845763776 bytes, 0 total output drops
     Output 0 broadcast packets, 0 multicast packets
     0 output errors, 0 underruns, 0 applique, 0 resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions

This example shows bundle member links whose link interface status is “err-disable” and line protocol state is “admin-down” after the bundle interface has been administratively shut down using the shutdown command: 


RP/0/RP0/CPU0:router# show interfaces brief

Thu May  6 06:30:55.797 DST

               Intf       Intf        LineP              Encap  MTU        BW
               Name       State       State               Type (byte)    (Kbps)
--------------------------------------------------------------------------------
               BE10        down        down               ARPA  1514          0
              BE100          up          up               ARPA  1514  100000000
              BE101          up          up               ARPA  1514  100000000
                Lo0          up          up           Loopback  1500          0
                Nu0          up          up               Null  1500          0
         Fo0/3/0/26  admin-down  admin-down               ARPA  1514   40000000
          Hu0/3/0/0  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/1  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/2  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/3  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/4  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/5  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/6  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/7  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/8  admin-down  admin-down               ARPA  1514  100000000
          Hu0/3/0/9  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/10  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/11  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/12  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/13        down        down               ARPA  1514  100000000
         Hu0/3/0/14          up          up               ARPA  1514  100000000
         Hu0/3/0/15          up          up               ARPA  1514  100000000
         Hu0/3/0/16  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/17  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/18          up          up               ARPA  1514  100000000
         Hu0/3/0/19          up          up               ARPA  1514  100000000
         Hu0/3/0/20  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/21  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/22  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/23  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/24          up          up               ARPA  1514  100000000
         Hu0/3/0/25  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/27  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/28  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/29  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/30  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/31  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/32  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/33  admin-down  admin-down               ARPA  1514  100000000
         Hu0/3/0/34        down        down               ARPA  1514  100000000
         Hu0/3/0/35          up          up               ARPA  1514  100000000
     Mg0/RP0/CPU0/0          up          up               ARPA  1514    1000000
     Mg0/RP1/CPU0/0          up          up               ARPA  1514    1000000

This example shows the output from the show interfaces counters rates physical command. 


RP/0/RP0/CPU0:router# show interfaces counters rates physical 

Fri Feb  3 23:06:45.101 UTC
InterfaceName               Intval     InMbps    InBW%    InKpps     OutMbps   OutBW%    OutKpps
HundredGigE0/0/0/0            0:03    93715.7   100.0%    32742.9     93715.6   100.0%     32742.8
HundredGigE0/0/0/35           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/34           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/33           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/32           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/31           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/30           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/29           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/28           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/27           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/26           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/25           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/24           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/13           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/11           0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/7            0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/6            0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/3            0:03        0.0     0.0%        0.0         0.0     0.0%         0.0
HundredGigE0/0/0/1            0:03    93715.7   100.0%    32742.9     93715.6   100.0%     32742.9
Table 2. show interfaces Field Descriptions

Field

Description

Interface name

Displays the name of the current interface. In the example, the interface name is TenGigE0/1/0/1.

Interface state

Displays the state of the interface. In the example, the interface is in the administratively down state.

Interface state transitions

Displays the number of times the interface has changed the state.

Note

 
  • Interface state transitions command counts only if the interface stays up. If the line protocol flaps, then it is not counted.

  • Interface state transitions counts the state when the line protocol state changes the state from up to down/admin-down or admin-down/down to up. If an interface changes the state from down to admin-down or admin-down to down, the counter is not incremented.

  • Use the clear state-transitions command to clear the counter for the current or all interfaces.

line protocol state

Displays the state of the Layer 2 line protocol. This field may be different from the interface state if, for example, a keepalive failure has brought down the Layer 2.

Note

 

The line protocol state is not the same as the protocol state displayed in the show ip interfaces command, because it is the state of Layer 2 (media) rather than Layer 3 (IP protocol).

Hardware

Displays the current hardware type.

address is n.n.n.n/n

Displays the Layer 2 address (MAC address for Ethernet interfaces).

Note

 

Enter the mac-address command to configure the hardware address.

bia

Displays the burned-in address (BIA) for the interface. The BIA is the default L2 (MAC) address for the interface.

Note

 

The BIA is not configurable.

description

Displays the user-defined string that is associated with the interface.

Note

 

Enter the description command to configure the description associated with the interface.

Internet address

Displays the Layer 3 (IP) address for the interface.

Note

 

Enter the ipv4 address command to configure the internet address for the interface.

MTU

Displays the maximum transmission unit (MTU) for the interface. The MTU is the maximum packet size that can be transmitted over the interface.

Note

 

The MTU field indicates the interface MTU. Enter the mtu command to configure a lower MTU value at the Layer 3 level.

BW

Displays the bandwidth of the interface in kbps.

reliability

Displays the proportion of packets that are not dropped and do not have errors.

Note

 

The reliability is shown as a fraction of 255.

txload

Indicates the traffic flowing out of the interface as a proportion of the bandwidth.

Note

 

The txload is shown as a fraction of 255.

rxload

Indicates the traffic flowing into the interface as a proportion of the bandwidth.

Note

 

The rxload is shown as a fraction of 255.

Encapsulation

Layer 2 encapsulation installed on the interface.

CRC

Indicates the length of the cyclic redundancy check (CRC), in bytes.

Note

 

The CRC is not present for all interface types.

Note

 

Enter the pos crc command to configure the CRC.

loopback or controller loopback

Indicates whether the hardware has been configured to be looped back.

Note

 

Enter the loopback command to configure the loopback or controller loopback.

keepalive

Displays the configured keepalive value, in seconds.

Note

 

Enter the keepalive command to configure the value of the keepalive field.

Note

 

The keepalive field may not be present if it is not applicable to the interface type.

Duplexity

Displays the duplexity of the link.

Note

 

This field is present only for shared media.

Note

 

For some interface types, you can configure the duplexity by entering the full-duplex and half-duplex commands.

Speed

Speed and bandwidth of the link in Mbps. This field is present only when other parts of the media info line are also displayed (see duplexity and media type).

Media Type

Media type of the interface.

output flow control

Whether output flow control is enabled on the interface.

input flow control

See output flow control.

ARP type

Address Resolution Protocol (ARP) type used on the interface. This value is not displayed on interface types that do not use ARP.

ARP timeout

ARP timeout in hours:mins:secs. This value is configurable using the arp timeout command.

Last clearing of counters

Time since the following counters were last cleared using the clear counters exec command in hours:mins:secs.

5 minute input rate

Average number of bits and packets received per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic that it sends and receives (rather than all network traffic).

Note

 

The 5-minute period referenced in the command output is a load interval that is configurable under the interface. The default value is 5 minutes.

Note

 

The 5-minute input should be used only as an approximation of traffic per second during a given 5-minute period. This rate is exponentially weighted average with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input

Number of packets received on the interface that were successfully delivered to higher layers.

bytes input

Total number of bytes successfully received on the interface.

total input drops

Total number of packets that were dropped after they were received. This includes packets that were dropped due to configured quality of service (QoS) or access control list (ACL) policies. This does not include drops due to unknown Layer 3 protocol.

Note

 

If CRC errors or giants occur, the total input drops increase. This behavior is unexpected and will be corrected in a future release.

drops for unrecognized upper-level protocol

Total number of packets that could not be delivered because the necessary protocol was not configured on the interface.

Received broadcast packets

Total number of Layer 2 broadcast packets received on the interface. This is a subset of the total input packet count.

Received multicast packets

Total number of Layer 2 multicast packets received on the interface. This is a subset of the total input packet count.

runts

Number of received packets that were too small to be handled. This is a subset of the input errors count.

giants

Number of received packets that were too large to be handled. This is a subset of the input errors count.

throttles

Number of packets dropped due to throttling (because the input queue was full).

parity

Number of packets dropped because the parity check failed.

input errors

Total number of received packets that contain errors and hence cannot be delivered.

Note

 

See total input drops for packets dropped due to CRC errors and giants.

CRC

Number of packets that failed the CRC check.

frame

Number of packets with bad framing bytes.

overrun

Number of overrun errors experienced by the interface. Overruns represent the number of times that the receiver hardware is unable to send received data to a hardware buffer because the input rate exceeds the receiver's ability to handle the data.

ignored

Total number of ignored packet errors. Ignored packets are those that are discarded because the interface hardware does not have enough internal buffers. Broadcast storms and bursts of noise can result in an increased number of ignored packets.

abort

Total number of abort errors on the interface.

packets output

Number of packets received on the interface that were successfully delivered to higher layers.

bytes output

Total number of bytes successfully received on the interface.

total output drops

Number of packets that were dropped before being transmitted

Received broadcast packets

Number of Layer 2 broadcast packets transmitted on the interface. This is a subset of the total input packet count.

Received multicast packets

Total number of Layer 2 multicast packets transmitted on the interface. This is a subset of the total input packet count.

output errors

Number of times that the receiver hardware was unable to handle received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.

underruns

Number of underrun errors experienced by the interface. Underruns represent the number of times that the hardware is unable to transmit data to a hardware buffer because the output rate exceeds the transmitter’s ability to handle the data.

applique

Number of applique errors.

resets

Number of times that the hardware has been reset. The triggers and effects of this event are hardware-specifc.

output buffer failures

Number of times that a packet was not output from the output hold queue because of a shortage of MEMD shared memory.

output buffers swapped out

Number of packets stored in main memory when the output queue is full; swapping buffers to main memory prevents packets from being dropped when output is congested. The number is high when traffic is bursty.

carrier transitions

Number of times the carrier detect (CD) signal of a serial interface has changed state.

Intval

Displays the time period in ms over which the rates are calculated.

InMbps

Displays the calculated input data rate for the interface in Mbps.

InBW%

Displays the percent input bandwidth utilization of the interface.

InKpps

Displays the calculated input packets rate for the interface in Kpps.

OutMbps

Displays the calculated output data rate for the interface in Mbps.

OutBW%

Displays the percent output bandwidth utilization of the interface.

OutKpps

Displays the calculated output packets rate for the interface in Kpps.