Cisco IOS IBM Networking Command Reference

enable (TN3270)

To turn on security in the TN3270 server, use the enable command in security configuration mode.

enable

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Security configuration

Command History

Usage Guidelines

There is not a no form for this command.

If the security command has been disabled, then issuing this command does not affect existing connections.

This command is not displayed in the show running-config command output because the security functionality is enabled by default.

Examples

The following example turns on security in the TN3270 server:

enable

Related Commands

encapsulation alc

To specify that the P1024B Airline Control (ALC) protocol will be used on the serial interface, use the encapsulation alc command in interface configuration mode. To remove ALC protocol handling from the serial interface, and return the default encapsulation high-level data link control (HDLC) to the interface, use the no form of this command.

encapsulation alc

no encapsulation alc

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Interface configuration

Command History

Usage Guidelines

The encapsulation alc command causes any agent-set control unit (ASCU) configuration to be removed from the interface. As each ASCU defined on the interface is removed it is also unlinked from the ASCU circuit it belongs to. All data frames queued for sending to the ASCU are destroyed.

This command must be entered prior to any ASCU configuration. Note that all timer and counter values are applicable to all ASCUs on the interface.

Examples

The following example specifies that the ALC protocol is used:

encapsulation alc

Related Commands

encapsulation bstun

To configure block serial tunnel (BSTUN) on a particular serial interface, use the encapsulation bstun command in interface configuration mode. To disable the BSTUN function on the interface, use the no form of this command.

encapsulation bstun

no encapsulation bstun

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Interface configuration

Command History

Usage Guidelines

The encapsulation bstun command must be configured on an interface before any further BSTUN or Bisync commands are configured for the interface.

You must use this command to enable BSTUN on an interface. Before using this command, perform the following two tasks:

•Enable BSTUN on a global basis by identifying BSTUN on IP addresses. The command is bstun peer-name.

•Define a protocol group number to be applied to the interface. Packets travel only between interfaces that are in the same protocol group. The command is bstun protocol-group.

After using the encapsulation bstun command, use the bstun group command to place the interface in the previously defined protocol group.

Examples

The following example configures the BSTUN function on serial interface 0:

interface serial 0

 no ip address

 encapsulation bstun

Related Commands

encapsulation sdlc

To configure an Synchronous Data Link Control (SDLC) interface, use the encapsulation sdlc command in interface configuration mode. To deactivate the command, use the no form of this command.

encapsulation sdlc

no encapsulation sdlc

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled.

Command Modes

Interface configuration

Command History

Usage Guidelines

The encapsulation sdlc command must be used to configure an SDLC interface if you plan to implement data-link switching plus (DLSw+) or Frame Relay access support.

SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then send if they have outgoing data. When configured as primary and secondary nodes, Cisco routers are established as SDLC stations. Use the sdlc role interface configuration command to establish the role as primary or secondary.

In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.

If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to a FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.

Examples

The following example configures an SDLC interface:

interface serial 2/6

 no ip address

 encapsulation sdlc

Related Commands

encapsulation sdlc-primary

To configure the router as the primary Synchronous Data Link Control (SDLC) station if you plan to configure the SDLC Logical Link Control (SDLLC) media translation feature, use the encapsulation sdlc-primary command in interface configuration mode. To deactivate the command, use the no form of this command.

encapsulation sdlc-primary

no encapsulation sdlc-primary

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled.

Command Modes

Interface configuration

Command History

Usage Guidelines

The encapsulation sdlc-primary or encapsulation sdlc-secondary command must be used to configure an SDLC interface. To use the encapsulation sdlc-primary command, first select the interface on which you want to enable SDLC. Then establish the router as a primary station. Next, assign secondary station addresses to the primary station using the sdlc address command.

SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then send if they have outgoing data. When configured as primary and secondary nodes, Cisco routers are established as SDLC stations.

In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.

If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to an FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.

Examples

The following example shows how to configure serial interface 0 on your router to allow two SDLC secondary stations to attach through a modem-sharing device (MSD) with addresses C1 and C2:

! enter a global command if you have not already 

interface serial 0

 encapsulation sdlc-primary

 sdlc address c1

 sdlc address c2

Related Commands

encapsulation sdlc-secondary

To configure the router as a secondary Synchronous Data Link Control (SDLC) station if you plan to configure the SDLC Logical Link Control (SDLLC) media translation feature, use the encapsulation sdlc-secondary command in interface configuration mode. To deactivate the command, use the no form of this command.

encapsulation sdlc-secondary

no encapsulation sdlc-secondary

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled.

Command Modes

Interface configuration

Command History

Usage Guidelines

An encapsulation sdlc-primary or encapsulation sdlc-secondary command must be used to configure an SDLC interface. To use the encapsulation sdlc-secondary command, select the interface on which you want to enable SDLC. Then establish the router as a secondary station. Next, assign secondary station addresses to the primary station using the sdlc address command.

SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then send if they have outgoing data. When configured as primary and secondary nodes, Cisco devices are established as SDLC stations.

In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.

If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to a FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.

Examples

The following example establishes the router as a secondary SDLC station:

interface serial 0

 encapsulation sdlc-secondary

Related Commands

encapsulation stun

To enable serial tunnel (STUN) encapsulation on a specified serial interface, use the encapsulation stun command in interface configuration mode.

encapsulation stun

Syntax Description

This command has no arguments or keywords.

Defaults

STUN encapsulation is disabled.

Command Modes

Interface configuration

Command History

Usage Guidelines

Use this command to enable STUN on an interface. Before using this command, perform the following two tasks:

•Enable STUN on a global basis by identifying STUN on IP addresses. The command is stun peer-name.

•Define a protocol group number to be applied to the interface. Packets travel only between interfaces that are in the same protocol group. The command is stun protocol-group.

After using the encapsulation stun command, use the stun group command to place the interface in the previously defined protocol group.

To disable stun encapsulation, configure the default interface encapsulation using the encapsulation command and specify HDLC as the encapsulation type

There is not a no form for this command.

Examples

This partial configuration example shows how to enable serial interface 5 for STUN traffic:

! sample stun peer name and stun protocol-group global commands 

stun peer-name 10.108.254.6

stun protocol-group 2 sdlc

! 

interface serial 5 

! sample ip address command

no ip address

! enable the interface for STUN; must specify encapsulation stun 

! command to further configure the interface 

encapsulation stun 

! place interface serial 5 in previously defined STUN group 2

stun group 2 

! enter stun route command 

stun route 7 tcp 10.108.254.7 

Related Commands

encapsulation uts

To specify that the P1024C Universal Terminal Support (UTS) protocol will be used on the serial interface, use the encapsulation uts command in interface configuration mode. To remove P1024C UTS protocol handling from the serial interface and return the default encapsulation high-level data link control (HDLC) to the interface, use the no form of this command.

encapsulation uts

no encapsulation uts

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

The encapsulation uts command causes any agent-set control unit (agent-set control unit (ASCU)) configuration to be removed from the interface. As each ASCU defined on the interface is removed it is also unlinked from the ASCU circuit it belongs to. All data frames queued for sending to the ASCU are destroyed.

This command must be entered prior to any ASCU configuration. Note that all timer and counter values are applicable to all ASCUs on the interface.

Examples

The following example specifies that the P1024C UTS protocol is used:

encapsulation uts

Related Commands

encryptorder

To specify the security encryption algorithm for the Secure Socket Layer (SSL) Encryption Support feature, use the encryptorder command in profile configuration mode.

encryptorder [RC4] [RC2] [RC5] [DES] [3DES]

Syntax Description

Defaults

The default encryption order is RC4, RC2, RC5, DES, 3DES for domestic software. The default encryption order is RC4, RC2, DES for exportable software.

Command Modes

Profile configuration

Command History

Usage Guidelines

There is not a no form for this command.

These algorithms may be entered in any order, but can be specified only once per encryptorder command.

Exportable versions of software cannot accept the 3DES or RC5 encryption algorithms.

Examples

The following example specifies RC4, DES, and RC2 as the encryption algorithms:

tn3270

 security

 profile DOMESTIC SSL

  encryptorder RC4 DES RC2

ethernet-transit-oui

To choose the Organizational Unique Identifier (OUI) code to be used in the encapsulation of Ethernet Type II frames across Token Ring backbone networks, use the ethernet-transit-oui command in subinterface configuration mode. Various versions of this OUI code are used by Ethernet/Token Ring translational bridges. To return the default OUI code, use the no form of this command.

ethernet-transit-oui [90-compatible | standard | cisco]

no ethernet-transit-oui

Syntax Description

Defaults

The default OUI form is 90-compatible.

Command Modes

Interface configuration

Command History

Usage Guidelines

Before using this command, you must have completely configured your router using multiport source bridging and transparent bridging.

The standard keyword is used when you are forced to interoperate with other vendor equipment, such as the IBM 8209, in providing Ethernet and Token Ring mixed media bridged connectivity.

Table 12 shows the actual OUI codes used, when they are used, and how they compare to Software Release 9.0-equivalent commands.

Specify the 90-compatible keyword when talking to our routers. This keyword provides the most flexibility. When 90-compatible is specified or the default is used, Token Ring frames with an OUI of 0x0000F8 are translated into Ethernet Type II frames and Token Ring frames with the OUI of 0x000000 are translated into Subnetwork Access Protocol (SNAP)-encapsulated frames. Specify the standard keyword when talking to IBM 8209 bridges and other vendor equipment. This OUI does not provide for as much flexibility as the other two choices. The cisco keyword oui is provided for compatibility with future equipment.

Do not use the standard keyword unless you are forced to interoperate with other vendor equipment, such as the IBM 8209, in providing Ethernet and Token Ring mixed media bridged connectivity. Only use the standard keyword only when you are transferring data between IBM 8209 Ethernet/Token Ring bridges and routers running the source-route translational bridging (SR/TLB) software (to create a Token Ring backbone to connect Ethernets).

Use of the standard keyword causes the OUI code in Token Ring frames to always be 0x000000. In the context of the standard keyword, an OUI of 0x000000 identifies the frame as an Ethernet Type II frame. (Compare with 90-compatible, where 0x000000 OUI means SNAP-encapsulated frames.)

If you use the 90-compatible keyword, the router, acting as an SR/TLB, can distinguish immediately on Token Ring interfaces between frames that started on an Ethernet Type II frame and those that started on an Ethernet as a SNAP-encapsulated frame. The distinction is possible because the router uses the 0x0000F8 OUI when converting Ethernet Type II frames into Token Ring SNAP frames, and leaves the OUI as 0x000000 for Ethernet SNAP frames going to a Token Ring. This distinction in OUIs leads to efficiencies in the design and execution of the SR/TLB product; no tables need to be kept to know which Ethernet hosts use SNAP encapsulation and which hosts use Ethernet Type II.

The IBM 8209 bridges, however, by using the 0x000000 OUI for all the frames entering the Token Ring, must take extra measures to perform the translation. For every station on each Ethernet, the 8209 bridges attempt to remember the frame format used by each station, and assume that once a station sends out a frame using Ethernet Type II or 802.3, it will always continue to do so. It must do this because in using 0x000000 as an OUI, there is no way to distinguish between SNAP and Type II frame types. Because the SR/TLB router does not need to keep this database, when 8209 compatibility is enabled with the standard keyword, the SR/TLB chooses to translate all Token Ring SNAP frames into Ethernet Type II frames as described earlier in this discussion. Because every nonroutable protocol on Ethernet uses either non-SNAP 802.3 (which traverses fully across a mixed IBM 8209/ router Token Ring backbone) or Ethernet Type II, this results in correct inter connectivity for virtually all applications.

Do not use the standard keyword OUI if you want SR/TLB to output Ethernet SNAP frames. Using either the 90-compatible or cisco keyword OUI does not present such a restriction, because SNAP frames and Ethernet Type II-encapsulated frames have different OUI codes on Token Ring networks.

Examples

The following example specifies standard OUI form:

interface tokenring 0

 ethernet-transit-oui standard

Related Commands

exception slot

To provide a core dump of a Cisco Mainframe Channel Connection (CMCC) adapter, use the exception slot command in global configuration mode. To disable the core dump, use the no form of this command.

exception slot [slot] protocol://host/filename

no exception slot [slot] protocol://host/filename

Syntax Description

Defaults

No default behavior or values

Command Modes

Global configuration

Command History

Usage Guidelines

This command is supported only on the Cisco 7000 with RSP7000 and Cisco 7500 series routers.

You must configure FTP services on the router before you can create a CMCC adapter core dump.

Do not exceed your host limits on filename length. Two characters are added to the filename, slot, where slot is the slot number.

Examples

The following example shows how to configure a router to perform a CMCC adapter core dump. Assuming the Channel Interface Processor (CIP) is installed in slot 3, the filename cipdump.3 will be written to the host.

ip domain-name cisco.com

ip name-server 168.69.161.21

ip ftp username tech1

ip ftp password tech1

exception slot ftp://168.18.2.196/cipdump

Related Commands

frame-relay map bridge broadcast

To bridge over a Frame Relay network, use the frame-relay map bridge broadcast command in interface configuration mode. To delete the mapping entry, use the no form of this command.

frame-relay map bridge dlci broadcast

no frame-relay map bridge dlci broadcast

Syntax Description

Defaults

No mapping entry is established.

Command Modes

Interface configuration

Command History

Usage Guidelines

Bridging over a Frame Relay network is supported on networks that do and do not support a multicast facility.

The following example allows bridging over a Frame Relay network:

frame-relay map bridge 144 broadcast

Related Commands

frame-relay map bstun

To configure block serial tunnel (BSTUN) over Frame Relay for pass-through, use the frame-relay map bstun command in interface configuration mode. To cancel the configuration, use the no form of this command.

frame-relay map bstun dlci

no frame-relay map bstun dlci

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

Direct encapsulation over Frame Relay is supported only for an encapsulation type of cisco, configured using the encapsulation frame-relay command.

Examples

The following example maps BSTUN traffic to DLCI number 16:

frame-relay map bstun 16

Related Commands

frame-relay map llc2

To configure block serial tunnel (BSTUN) over Frame Relay when using Bisync local acknowledgment, use the frame-relay map llc2 command in interface configuration mode. To cancel the configuration, use the no form of this command.

frame-relay map llc2 dlci

no frame-relay map llc2 dlci

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

Direct encapsulation over Frame Relay is supported only for an encapsulation type of cisco, configured using the encapsulation frame-relay command.

Examples

The following example maps BSTUN traffic to data-link connection identifier (DLCI) number 16:

frame-relay map dlci 16

Related Commands

frame-relay map rsrb

To specify the data-link connection identifier (DLCI) number onto which the remote source-route bridging (RSRB) traffic is to be mapped, use the frame-relay map rsrb command in interface configuration mode. To cancel the RSRB map, use the no form of this command.

frame-relay map rsrb dlci

no frame-relay map rsrb

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

Direct encapsulation over Frame Relay is supported only for an encapsulation type of cisco, configured using the encapsulation frame-relay command.

Examples

The following example shows RSRB traffic mapped to DLCI number 30:

frame-relay map rsrb 30

Related Commands

fras backup dlsw

To configure an auxiliary route between the end stations and the host for use as a backup when the data-link connection identifier (DLCI) connection to the Frame Relay network is lost, use the fras backup dlsw command in interface configuration mode. To cancel the backup configuration, use the no form of this command.

fras backup dlsw virtual-mac-address target-ring-number host-mac-address [retry retry-number]

no fras backup dlsw virtual-mac-address target-ring-number host-mac-address [retry retry-number]

Syntax Description

Defaults

Frame Relay access support (FRAS) dial backup over data-link switching plus (DLSw+) is disabled. The default number of retries is 5.

Command Modes

Interface configuration

Command History

Usage Guidelines

Configure DLSw+ as normally required. Specify the optional keyword dynamic at the end of the dlsw remote-peer configuration command to enable the peer relationship to be established only when needed (for example, when the fras backup dlsw command becomes active).

Examples

The following example configures FRAS dial backup over DLSw+:

fras backup dlsw 4000.1000.2000 200 1000.5aed.1f53

Related Commands

fras ban

To associate bridging over a Frame Relay network using boundary access node (BAN), use the fras ban command in interface configuration mode. To cancel each association, use the no form of this command.

fras ban local-ring bridge-number ring-group ban-dlci-mac dlci dlci1 [dlci2 ... dlci5] [bni mac-addr]

no fras ban local-ring bridge-number ring-group ban-dlci-mac dlci dlci1 [dlci2 ... dlci5] [bni mac-addr]

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

Multiple fras ban commands may be configured; however, each fras ban command must use a unique DLCI MAC address.

You must configure the source-bridge ring-group command in global configuration mode prior to configuring the fras ban command.

Examples

The following example shows Frame Relay access support (FRAS) BAN support for Token Ring and serial interfaces:

source-bridge ring-group 200

!

interface serial 0

 mtu 4000

 encapsulation frame-relay ietf

 frame-relay lmi-type ansi

 frame-relay map llc2  16

 frame-relay map llc2  17

 fras ban 120 1 200 4000.1000.2000 dlci 16 17

!

interface tokenring 0

 source-bridge 100 5 200

Related Commands

fras ddr-backup

To configure an auxiliary interface for use as a backup when the primary Frame Relay link to the Frame Relay WAN fails, use the fras ddr-backup command in interface configuration mode. To cancel the backup configuration, use the no form of this command.

fras ddr-backup interface interface dlci-number

no fras ddr-backup

Syntax Description

Defaults

Frame Relay access support (FRAS) DLCI backup is disabled by default.

Command Modes

Interface configuration

Command History

Examples

The following example configures FRAS DLCI backup on serial interface 1:

fras ddr-backup interface serial 1 188

Related Commands

fras map llc

To associate an Logical Link Control (LLC) connection with a Frame Relay data-link connection identifier (DLCI), use the fras map llc command in interface configuration mode. To disable the association, use the no form of this command.

fras map llc lan-lsap serial interface frame-relay dlci dlci fr-rsap

no fras map llc lan-lsap serial interface frame-relay dlci dlci fr-rsap

Syntax Description

Defaults

The default state is Frame Relay access support (FRAS) boundary network node (BNN) enhancement is disabled.

Command Modes

Interface configuration

Command History

Usage Guidelines

If the destination SAP specified by the end station is equal to the lan-lsap value, the router associates the LLC (LAN) connection with the Frame Relay DLCI.

The MAC address and the SAP address of the end station are no longer required for the BNN enhanced configuration.

Examples

In the FRAS BNN enhancement, the revised fras map llc command achieves the same result as using multiple fras map llc commands in the original FRAS BNN implementation. The following example provides one map definition for both end stations:

fras map llc 4 Serial 0 frame-relay dlci 16 04

Related Commands

fras map sdlc

To associate an Synchronous Data Link Control (SDLC) link with a Frame Relay data-link connection identifier (DLCI), use the fras map sdlc command in interface configuration mode. To cancel the association, use the no form of this command.

fras map sdlc sdlc-address serial port frame-relay dlci fr-lsap fr-rsap [pfid2 | afid2 | fid4]

no fras map sdlc sdlc-address serial port frame-relay dlci fr-lsap fr-rsap [pfid2 | afid2 | fid4]

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

You can map multiple SDLC links to a DLCI.

Examples

The following example associates an SDLC link with a Frame Relay DLCI:

fras map sdlc c1 serial 0 frame-relay 200 4 4

Related Commands

fras-host ban

To enable the Frame Relay access support (FRAS) Host function for boundary access node (BAN), use the fras-host ban command in interface configuration mode. To disable the FRAS Host BAN functionality, use the no form of this command.

fras-host ban interface hmac hmac [bni bni]

no fras-host ban

Syntax Description

Defaults

The FRAS Host function for BAN is disabled for the Frame Relay subinterface.

The default bni value is 4FFF.0000.0000.

Command Modes

Interface configuration

Command History

Examples

The following example enables the FRAS Host function for BAN:

fras-host ban Serial0 hmac 4001.3745.0001

Related Commands

fras-host bnn

To enable the Frame Relay access support (FRAS) Host function for boundary network node (BNN), use the fras-host bnn command in interface configuration mode. To disable the FRAS Host function, use the no form of this command.

fras-host bnn interface fr-lsap sap vmac virt-mac hmac hmac [hsap hsap]

no fras-host bnn

Syntax Description

Defaults

FRAS Host for BNN is disabled for the Frame Relay subinterface.

Command Modes

Interface configuration

Command History

Examples

The following example enables the FRAS Host function for BNN:

fras-host bnn Serial0 fr-lsap 04 vmac 4005.3003.0000 hmac 4001.3745.0001

Related Commands

fras-host dlsw-local-ack

To enable Logical Link Control, type 2 (LLC2) local termination for Frame Relay access support (FRAS) Host connections using the virtual Token Ring, use the fras-host dlsw-local-ack command in interface configuration mode. To disable LLC2 local termination, use the no form of this command.

fras-host dlsw-local-ack

no fras-host dlsw-local-ack

Syntax Description

This command has no arguments or keywords.

Defaults

The default state is FRAS Host LLC2 local termination disabled.

Command Modes

Interface configuration

Command History

Examples

The following example enables LLC2 local termination for FRAS Host connections using the virtual Token Ring:

fras-host dlsw-local-ack

Related Commands

generic-pool

To specify whether leftover logical unit (LU)s will be made available to TN3270 sessions that do not request a specific LU or LU pool through TN3270E, use the generic-pool command in TN3270 server configuration mode. To selectively remove the permit or deny condition of generic pool use, use the no form of this command.

generic-pool {permit | deny}

no generic-pool

Syntax Description

Defaults

In TN3270 server configuration mode, generic pool use is permitted.

In PU configuration mode, the default is the value configured in TN3270 server configuration mode.

Command Modes

TN3270 server configuration
Listen-point configuration
Listen-point PU configuration
Dependent Logical Unit Requestor (DLUR) PU configuration
PU configuration

Command History

Usage Guidelines

This command is valid only on the virtual channel interface.

A leftover LU is defined as one for which all of the following conditions are true:

•The system services control point (SSCP) did not send an activate logical unit (ACTLU) during PU startup.

•The PU controlling the LU is capable of carrying product set ID (PSID) vectors on network management vector transport (NMVT) messages, thus allowing dynamic definition of dependent LU (DDDLU) operation for that LU.

All LUs in the generic pool are, by definition, DDDLU capable.

Values entered for the generic-pool in the TN3270 server configuration mode apply to all PUs for that TN3270 server but can be changed in PU configuration mode.

In PU configuration mode, a no generic-pool command will restore the generic-pool value entered in TN3270 command mode.

In TN3270 server configuration mode, the no generic-pool command reverts to the default, which permits generic pool use.

The command takes effect immediately. If the generic-pool deny command is specified on a PU, no further dynamic connections to it will be allowed. Existing sessions are unaffected, but as they terminate the LUs will not become available for dynamic connections.

Similarly, if the generic-pool permit command is specified, any inactive LUs are immediately available for dynamic connections. Moreover, any active LUs that were dynamic previously (before the generic-pool deny command was issued) return to being dynamic.

Examples

The following example permits generic LU pool use:

generic-pool permit

Related Commands

idle-time

To specify seconds of logical unit (LU) inactivity, from both host and client, before the TN3270 session is disconnected, use the idle-time command in TN3270 server configuration mode. To cancel the idle time period and return to the default, use the no form of this command.

idle-time seconds

no idle-time

Syntax Description

Defaults

The default in TN3270 server configuration mode is that the session is never disconnected (0).

The default in PU configuration mode is the value configured in TN3270 server configuration mode.

Command Modes

TN3270 server configuration
Listen-point configuration
Listen-point PU configuration
Dependent Logical Unit Requestor (DLUR) PU configuration
PU configuration

Command History

Usage Guidelines

The idle-time command is valid only on the virtual channel interface, and can be entered in either TN3270 server configuration mode or PU configuration mode. A value entered in TN3270 mode applies to all PUs for that TN3270 server, except as overridden by values entered in PU configuration mode.

A no idle-time command entered in PU configuration mode will restore the idle-time value entered in TN3270 command mode.

The idle-time command affects active and future TN3270 sessions. For example, if the idle-time value is reduced from 900 seconds to 600 seconds, sessions that have been idle for 600 to 900 seconds are immediately disconnected.

Note For the purposes of idle-time logic, TIMING-MARKs generated by the keepalive logic do not constitute "activity."

In TN3270 server configuration mode, the idle-time command applies to all PUs supported by the TN3270 server.

In listen-point configuration mode, the idle-time command applies to all PUs defined at the listen point.

In listen-point PU configuration mode, the idle-time command applies only to the specified PU.

In DLUR PU configuration mode, the idle-time command applies to all PUs defined under DLUR configuration mode.

In PU configuration mode, the idle-time command applies only to the specified PU.

Examples

The following command sets an idle-time disconnect value of 10 minutes:

idle-time 600

The following command entered in TN3270 server configuration mode sets the default idle-time disconnect value to 0, or never disconnect:

no idle-time

Related Commands

interface bvi

To create the bridge-group virtual interface (BVI) that represents the specified bridge group to the routed interface and links the corresponding bridge group to the other routed interfaces, use the interface bvi command in global configuration mode. To delete the BVI, use the no form of this command.

interface bvi bridge-group

no interface bvi bridge-group

Syntax Description

Command Default

No BVI is created.

Command Modes

Global configuration (config)

Command History

Usage Guidelines

You must enable integrated routing and bridging (IRB) before attempting to create a BVI.

When you intend to bridge and route a given protocol in the same bridge group, you must configure the network-layer attributes of the protocol on the BVI. Do not configure protocol attributes on the bridged interfaces. Bridging attributes cannot be configured on the BVI.

Examples

The following example creates a bridge group virtual interface and associates it with bridge group 1:

Router(config)# bridge 1 protocol ibm

Router(config)# bridge irb

Router(config)# interface bvi 1

Router(config-if)#

Related Commands

interface channel

To specify a channel-attached interface and enter interface configuration mode, use the interface channel command in global configuration mode.

interface channel slot/port

Syntax Description

Defaults

No default behavior or values

Command Modes

Global configuration

Command History

Examples

The following example shows how to enter interface configuration mode for a CIP in slot 2 and begin configuring port 0:

interface channel 2/0

Related Commands

interface virtual-tokenring

To create a virtual Token Ring interface, use the interface virtual-tokenring command in global configuration mode. To cancel the configuration, use the no form of this command.

interface virtual-tokenring number

no interface virtual-tokenring

Syntax Description

Defaults

No default behavior or values

Command Modes

Global configuration

Command History

Examples

The following example configures the virtual Token Ring interface:

interface virtual-tokenring 0

Related Commands

interface vlan

To create a dynamic Switch Virtual Interface (SVI) or configure a Route Switch Module (RSM), use the interface vlan command in global configuration mode.

Configuring on an RSM

To configure a Token Ring or Ethernet interface on the RSM, use the interface vlan command in global configuration mode.

interface vlan vlanid type {trbrf | ethernet}

Creating a Dynamic Switch Virtual Interface

To create or access a dynamic SVI, use the interface vlan command in global configuration mode. Use the no form of this command to delete an SVI.

interface vlan vlanid

no interface vlan vlanid

Syntax Description

Defaults

Configuring on an RSM

RSM interfaces are not configured.

Creating a Dynamic Switch Virtual Interface

Fast EtherChannel is not specified.

Command Modes

Global configuration

Command History

Usage Guidelines

Configuring on an RSM

Valid Token Ring VLAN ID numbers are 2 through 1000.

Routing or bridging to a Token Ring VLAN (TrBRF) on the RSM is done by creating a logical interface to a TrBRF VLAN on the RSM with the interface vlan command. The TrBRF VLAN must be defined on the Supervisor module prior to creating the TrBRF interface on the RSM.

Creating a Dynamic Switch Virtual Interface

SVIs are created the first time that you enter the interface vlan vlan-id command for a particular VLAN. The vlan-id value corresponds to the VLAN tag that is associated with the data frames on an Inter-Switch Link (ISL), the 802.1Q-encapsulated trunk, or the VLAN ID that is configured for an access port. A message displays whenever you create a new VLAN interface, so that you can check if you entered the correct VLAN number.

If you delete an SVI by entering the no interface vlan vlan-id command, the associated initial domain part (IDP) pair is forced into an administrative down state and is marked as deleted. The deleted interface will not be visible in the show interface command.

You can reinstate a deleted SVI by entering the interface vlan vlan-id command for the deleted interface. The interface comes back up, but much of the previous configuration is gone.

VLANs 1006 to 1014 are internal VLANs on the Cisco 7600 series router and cannot be used for creating new VLANs.

Examples

Configuring on an RSM

The following example show how to configure an RSM Token Ring interface with VLAN 998:

Router(config)# interface vlan 998 type trbrf

 ip address 10.5.5.1 255.255.255.0

Creating a Dynamic Switch Virtual Interface

The following example shows the output when you enter the interface vlan vlan-id command for a new VLAN number:

Router(config)# interface vlan 23

% Creating new VLAN interface.

Related Commands

ip precedence (TN3270)

To specify the precedence level for voice over IP traffic in the TN3270 server, use the ip precedence command in TN3270 server configuration mode. To remove the precedence value, use the no form of this command.

ip precedence {screen | printer} value

no ip precedence {screen | printer}

Syntax Description

Defaults

The default is a precedence value of 0 for both screens and printers.

Command Modes

TN3270 server configuration
Listen-point configuration
Listen-point PU configuration
Dependent Logical Unit Requestor (DLUR) PU configuration
PU configuration

Command History

Usage Guidelines

This command is valid only on the virtual channel interface. Precedence values applied in TN3270 PU configuration mode override values applied in TN3270 server configuration mode.

You can enter new or different values for IP precedence without first using the no form of this command.

During initial Telnet negotiations to establish, or bind, the session an IP precedence value of 0 and IP ToS value of 0 is used. These values are used until the bind takes place. When the session is a type 2 bind, the TN3270 client is assumed to be a screen; otherwise the client is assumed to be a printer.

In TN3270 server configuration mode, the ip precedence command applies to all PUs supported by the TN3270 server.

In listen-point configuration mode, the ip precedence command applies to all PUs defined at the listen point.

In listen-point PU configuration mode, the ip precedence command applies only to the specified PU.

In DLUR PU configuration mode, the ip precedence command applies to all PUs defined under DLUR configuration mode.

In PU configuration mode, the ip precedence command applies only to the specified PU.

Examples

The following example assigns a precedence value of 3 to printers:

ip precedence printer 3

Related Commands

ip tos

To specify the type of service (ToS) level for IP traffic in the TN3270 server, use the ip tos command in TN3270 server configuration mode. To remove the ToS value, use the no form of this command.

ip tos {screen | printer} value

no ip tos {screen | printer}

Syntax Description

Defaults

The default is a ToS value of 0 for both screens and printers.

Command Modes

TN3270 server configuration
Listen-point configuration
Listen-point PU configuration
Dependent Logical Unit Requestor (DLUR) PU configuration
PU configuration

Command History

Usage Guidelines

This command is valid only on the virtual channel interface. ToS values applied in TN3270 PU configuration mode override values applied in TN3270 server configuration mode.

The default ToS values for screen and printer are 0. However, RFC 1349 recommends different default values. Specifically, the RFC recommends a default minimize screen delay value of 8 and a default maximize printer throughput value of 4. You must configure these values using the ip tos command if you want to comply to the defaults as stated in the RFC.

Table 13 shows the values described in RFC 1349.

.

During initial Telnet negotiations to establish, or bind, the session, an IP precedence value of 0 and IP ToS value of 0 is used. These values are used until the bind takes place. When the session is a type 2 bind, the TN3270 client is assumed to be a screen; otherwise the client is assumed to be a printer.

When you use the no form of the command, the ToS value is set to 0 for that configuration mode or the value set at a previous (higher) configuration mode is used. For example, if you are at the TN3270 PU configuration mode and issue a no ip tos screen command, any value you configured previously at the TN3270 server configuration mode will take effect.

You can enter new or different values for ToS without first using the no form of this command.

In TN3270 server configuration mode, the ip tos command applies to all PUs supported by the TN3270 server.

In listen-point configuration mode, the ip tos command applies to all PUs defined at the listen point.

In listen-point PU configuration mode, the ip tos command applies only to the specified PU.

In DLUR PU configuration mode, the ip tos command applies to all PUs defined under DLUR configuration mode.

In PU configuration mode, the ip tos command applies only to the specified PU.

Examples

In the following example, the TN3270 server ToS screen value is set to 10 and a specific PU ToS screen value is set to 0:

interface channel 3/2 
  tn3270-server 
   ip tos screen 8 
   ip tos printer 4 
  up PUS2 
   ip tos screen 0

Related Commands

keepalive (TN3270)

To specify how many seconds of inactivity elapse before the TN3270 server sends a DO TIMING-MARK or Telnet no operation (nop) to the TN3270 client, use the keepalive command in TN3270 server configuration mode. To cancel the keepalive period and return to the previously configured siftdown value or the default, use the no form of this command.

keepalive seconds [send {nop | timing-mark [max-response-time]}]

no keepalive

Syntax Description

Defaults

The default behavior is to send timing marks with a keepalive interval of 1800 seconds (30 minutes). If you specify only the keepalive interval, the TN3270 server sends timing marks.

The default value of the send timing-mark max-response-time command is 30 seconds if the keepalive interval is greater than or equal to 30 seconds. If the value of the keepalive interval is less than 30 seconds, then the default max-response-time value is the value of the interval.

Command Modes

TN3270 server configuration
Listen-point configuration
Listen-point PU configuration
Dependent Logical Unit Requestor (DLUR) PU configuration
PU configuration

Command History

Usage Guidelines

The keepalive command is valid only on the virtual channel interface. This command can be entered in one of four command modes (TN3270 configuration, listen-point configuration, listen-point PU configuration, or PU configuration mode). A value entered in TN3270 mode applies to all PUs for that TN3270 server, except as overridden by values entered in the other supported configuration modes. A no keepalive command entered in a subsequent configuration mode will restore the keepalive value entered in the previous command mode.

In Cisco IOS releases prior to 12.0(5)T in which the keepalive command is supported, you cannot specify the period of time in which the client must respond to the DO TIMING-MARK before the TN3270 server disconnects the session. By default in prior releases, if the client does not reply within 30 minutes of sending the DO TIMING-MARK, the TN3270 server disconnects the TN3270 session. (The DO TIMING-MARK is a Telnet protocol operation that does not affect the client operation.)

With the addition of the send timing-mark max-response-time keywords in Cisco IOS Release 12.0(5)T, you can specify the period of time in which the client must respond to the DO TIMING-MARK before being disconnected by the server. If you do not specify a value for the max-response-time argument, the default value is determined by the size of the keepalive interval. The default is 30 seconds if the keepalive interval is greater than or equal to 30 seconds. If the value of the keepalive interval is less than 30 seconds, then the default max-response-time is the value of the interval.

If the IP path to the client is broken, the TCP layer will detect the failure to acknowledge the DO TIMING-MARK and initiate disconnection. This action usually takes much less than 30 seconds.

The keepalive command affects active and future TN3270 sessions. For example, reducing the keepalive interval to a lower nonzero value causes an immediate burst of DO TIMING-MARKs on those sessions that have been inactive for a period of time greater than the new, lower value.

Use the keepalive send nop command when you are using older TN3270 clients that do not support TIMING-MARK or are DOS-based clients. When you use the keepalive send nop command to monitor the client connection, no response is required by the client to the TN3270 server. However, the TCP/IP stack can detect that the physical connection still exists. This command is useful for those clients that can be swapped out when a DO TIMING-MARK has been sent by the TN3270 server. If the client is swapped out and cannot respond to the DO TIMING-MARK from the TN3270 server, the session is disconnected. However, if the client is swapped out and the Telnet nop command is sent by the server, the physical connection is still verifiable by the TCP/IP stack and the client remains connected to the server.

If your client supports the use of timing marks and is not subject to being swapped out, then using timing marks is preferable to the Telnet nop command for keepalive monitoring. The required response by TN3270 clients to timing marks sent by the server provides a better indication of the health of the client/server connection.

In TN3270 server configuration mode, the keepalive command applies to all PUs supported by the TN3270 server.

In listen-point configuration mode, the keepalive command applies to all PUs defined at the listen point.

In listen-point PU configuration mode, the keepalive command applies only to the specified PU.

In DLUR PU configuration mode, the keepalive command applies to all PUs defined under DLUR configuration mode.

In PU configuration mode, the keepalive command applies only to the specified PU.

Examples

The following example specifies that the TN3270 server sends a DO TIMING-MARK in 15-minute (900-second) intervals and the client must respond within 30 seconds (the default value for the timing-mark max-response-time command when not specified):

keepalive 900

The following example entered in TN3270 server configuration mode specifies that the TN3270 server sends a DO TIMING-MARK in 30-minute (1800-second) intervals (the default interval) and the client must respond within 30 seconds (the default for the timing-mark max-response-time command when not specified):

no keepalive

The following example specifies that the TN3270 server sends a DO TIMING-MARK in 40-minute (2400-second) intervals and the client must respond within 1 minute (60 seconds):

keepalive 2400 send timing-mark 60

Consider the following example in which the keepalive command is configured in more than one command mode. In this example the keepalive command is configured in TN3270 server configuration mode, and then in listen-point physical unit (PU) configuration mode. The keepalive command values specified under the listen-point PU override the keepalive 300 value specified under the tn3270-server for PU1. In this example, all other PUs except PU1 use the value of the keepalive 300 command specified in TN3270 server configuration mode.

tn3270-server

keepalive 300

listen-point 10.10.10.1 tcp-port 40

  pu PU1 94223456 tok 1 08

    keepalive 10 send timing-mark 5

  pu PU2 94223457 tok 2 12

Related Commands

keylen

To specify the maximum bit length for the encryption keys for Secure Socket Layer (SSL) Encryption Support, use the keylen 128 command in profile configuration mode. To disable this specification and thereby set the key length to the default of 40 bits, use the no form of this command or keylen 40.

keylen {40 | 128}

no keylen [40 | 128]

Syntax Description

Defaults

The default encryption key length is 40 bits.

Command Modes

Profile configuration.

Command History

Usage Guidelines

Exportable software versions cannot accept encryption key lengths greater than 40 bits.

The length is optional on the no form of this command. Entering the no form of this command with no length resets the length to the default value of 40 bits.

If the key length is changed, all new connections will use the new value. If an active session renegotiates its security specifications, it will use the new key length value.

Examples

The following example specifies the maximum encryption key length value to 128 bits:

tn3270-server

 security

 profile DOMESTIC SSL

  encryptorder RC4 DES RC2

  keylen 128

lan

To configure an internal LAN on a Cisco Mainframe Channel Connection (CMCC) adapter interface and enter internal LAN configuration mode, use the lan command in interface configuration mode. To remove an internal LAN interface, use the no form of this command.

lan type lan-id

no lan type lan-id

Syntax Description

Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Usage Guidelines

Token Ring is the only type of internal LAN supported.

This command is valid only on the virtual channel interface. All internal adapters configured on the internal LAN must be removed before the internal LAN can be removed.

A CMCC internal LAN can be configured as a SRB LAN. This allows Logical Link Control (LLC) packets to be bridged between the CMCC adapter and Cisco IOS, providing a means to link the internal LAN to Cisco IOS Systems Network Architecture (SNA) features such as source-route bridging (SRB), data-link switching plus (DLSw+), remote source-route bridging (RSRB), SDLC Logical Link Control (SDLLC), Qualified Logical Link Control (QLLC), Advanced Peer-to-Peer Networking (APPN), and source-route translational bridging (SR/TLB).

An internal LAN can be configured only on a virtual channel interface of a CMCC adapter. You enter first internal LAN configuration mode by issuing the command for an internal LAN that already exists or when you first configure an internal LAN. In internal LAN configuration mode, the router prompt appears as follows:

router (cfg-lan-type x) #

In this syntax, type is the specified internal LAN type and x is the specified value for the lan-id.

Examples

The following example shows how to configure an internal LAN Token Ring with a LAN ID of 20 on the channel interface 1/2:

interface channel 1/2

 lan tokenring 20

Related Commands

lan-name

To specify a name for the LAN that is attached to the interface, use the lan-name command in interface configuration mode. This name is included in any Alert sent to the Systems Network Architecture (SNA) host when a problem occurs on this interface or LAN. To revert to the default name, use the no form of this command.

lan-name lan-name

no lan-name lan-name

Syntax Description

Defaults

The default name used for the LAN is the name of the interface.

Command Modes

Interface configuration

Command History

Examples

The following example identifies a LAN:

lan-name LAN1

Related Commands

link (TN3270)

To define and activate a link to a host, use the link command in Dependent Logical Unit Requestor (DLUR) service access point (SAP) configuration mode. To delete the link definition, use the no form of this command.

link name [rmac rmac] [rsap rsap]

no link name

Syntax Description

Defaults

No DLUR link is defined.
The default remote SAP address is 04 (hexadecimal).

Command Modes

DLUR SAP configuration

Command History

Usage Guidelines

This command is valid only on the virtual channel interface. The combination of the rmac and rsap value must be unique within the DLUR SAP function. These values can be changed only by deleting the link definition, using the no link command, and recreating the link definition.

For a link via a channel on this Cisco Mainframe Channel Connection (CMCC) adapter, the TN3270 server and the hosts should open different adapters. Using different adapters avoids any contention for SAP numbers, and is also necessary if you configure duplicate MAC addresses for fallback Cisco Systems Network Architecture (CSNA) or Cisco Multipath Channel (CMPC) access to the host.

Examples

The following example defines a link name and a remote SAP address:

link LINK5 rsap 08

The following example shows different adapter numbers configured on the same internal LAN to avoid SAP contention. The host uses SAP 4 on Token Ring adapter 0.

lan tokenring 0

 adapter 0 4000.0000.0001

 adapter 1 4000.0000.0002

tn3270-server

 dlur ...

 lsap token-adapter 1

  link HOST rmac 4000.0000.0001 rsap 4

Related Commands

listen-point

To define an IP address for the TN3270 server, use the listen-point command in TN3270 server configuration mode. To remove a listen-point for the TN3270 server, use the no form of this command.

listen-point ip-address [tcp-port number]

no listen-point ip-address [tcp-port number]

Syntax Description

Defaults

The default tcp-port number is 23.

Command Modes

TN3270 server configuration

Command History

Usage Guidelines

Use the listen-point command to create a unique listen point for every IP address and TCP-port pair. In this mode, the IP address and the TCP port are no longer configured in the PU. Configure the PUs under the appropriate listen point. The other siftdown configuration commands remain the same.

For example, in the old configuration the following statements were used to configure the IP address and TCP port in the PU:

tn3270-server

  pu PU1 94223456 10.10.10.1 tok 1 08

   tcp-port 40

   keepalive 10

In the new listen-point configuration, the following statements are used to configure the IP address and TCP port at the listen point:

tn3270-server

  listen-point 10.10.10.1 tcp-port 40

   pu PU1 94223456 tok 1 08

    keepalive 10

You can also use the listen-point configuration to assign the same IP address to multiple PUs. In the old configuration the following statements were used:

tn3270-server

  pu PU1 94201231 10.10.10.2 tok 1 10

  pu PU2 94201232 10.10.10.3 tok 1 12

  pu PU3 94201234 10.10.10.3 tok 1 14

  pu PU4 94201235 10.10.10.4 tok 1 16

   tcp-port 40

  pu PU5 94201236 10.10.10.4 tok 2 08

In the new listen point configuration, the old statements are replaced by the following configuration commands. In this example, PU2 and PU3 are grouped into one listen point because they have the same IP address. Note that even though PU4's IP address is identical to PU5's IP address, they are not configured within the same listen point because the listen point indicates a unique IP address and TCP port pair. If you do not specify the TCP port, the default port value is 23.

tn3270-server

 listen-point 10.10.10.2

  pu PU1 94201231 tok 1 10

 listen-point 10.10.10.3

  pu PU2 94201232 tok 1 12

  pu PU3 94201234 tok 1 14

 listen-point 10.10.10.4

  pu PU5 94201236 tok 2 08

 listen-point 10.10.10.4 tcp-port 40

  pu PU4 94201235 tok 1 16

The next example shows how the configuration changes for a Dependent Logical Unit Requestor (DLUR) PU. In this mode, the DLUR PU is no longer configured under DLUR, but is configured in the listen point.

In the old configuration, the following statements were used:

tn3270-server

 dlur NETA.RTR1 NETA.HOST

  dlus-backup NETA.HOST

  lsap token-adapter 15 08

   link MVS2TN rmac 4000.b0ca.0016

  pu PU1 017ABCDE 10.10.10.6

These statements are replaced by the following statements in the new listen-point configuration. The keyword dlur differentiates the listen point direct PU from the listen point DLUR PU. The DLUR configuration must be completed before you configure the PU in the listen point. Any siftdown commands configured within the scope of the listen point are automatically inherited by the PUs that are configured within the scope of that listen point. To override the siftdown configurations, you can explicitly configure the siftdown configuration commands within the scope of the listen-point PU.

tn3270-server

 dlur NETA.RTR1 NETA.HOST

  dlus-backup NETA.HOST

  lsap token-adapter 15 08

   link MVS2TN rmac 4000.b0ca.0016

 listen-point 10.10.10.6

  pu PU1 017ABCDE dlur

Examples

The following example of the listen-point command shows PU7 grouped into the listen point at IP address 10.10.10.1 and TCP port 40:

tn3270-server

listen-point 10.10.10.1 tcp-port 40

 pu PU7 94201237 tok 1 17

Related Commands

llc2 ack-delay-time

To set the amount of time the Cisco IOS software waits for an acknowledgment before sending the next set of information frames, use the llc2 ack-delay-time command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 ack-delay-time milliseconds

no llc2 ack-delay-time milliseconds

Syntax Description

Defaults

100 ms

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

Upon receiving an information frame, each Logical Link Control, type 2 (LLC2) station starts a timer. If the timer expires, an acknowledgment will be sent for the frame, even if the number of received frames in the llc2 ack-max command has not been reached. Experiment with the value of the llc2 ack-delay-time command to determine the configuration that balances acknowledgment network overhead and quick response time (by receipt of timely acknowledgments).

Use this command in conjunction with the llc2 ack-max command to determine the maximum number of information frames the Cisco IOS software can receive before sending an acknowledgment.

Examples

In the following example, the software allows a 100-ms delay before I-frames must be acknowledged:

! enter a global command, if you have not already

interface tokenring 0

! sample ack-max command 

 llc2 ack-max 3

! allow a 100 millisecond delay before I-frames must be acknowledged

 llc2 ack-delay-time 100

At time 0, two information frames are received. The llc2 ack-max amount of three has not been reached, so no acknowledgment for these frames is sent. If a third frame, which would force the software to send an acknowledgment, is not received in 100 ms, an acknowledgment will be sent anyway, because the llc2 ack-delay timer expires. At this point, because all frames are acknowledged, the counter for the ack-max purposes will be reset to zero.

Related Commands

llc2 ack-max

To control the maximum amount of information frames the Cisco IOS software can receive before it must send an acknowledgment, use the llc2 ack-max command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 ack-max packet-count

no llc2 ack-max packet-count

Syntax Description

Defaults

Three packets

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

An Logical Link Control, type 2 (LLC2)-speaking station can send only a predetermined number of frames before it must wait for an acknowledgment from the receiver. If the receiver waits until receiving a large number of frames before acknowledging any of them, and then acknowledges them all at once, overhead is reduced on the network.

For example, an acknowledgment for five frames can specify that all five have been received, as opposed to sending a separate acknowledgment for each frame. To keep network overhead low, make this parameter as large as possible.

However, some LLC2-speaking stations expect this number to be low. Some NetBIOS-speaking stations expect an acknowledgment to every frame. Therefore, for these stations, this number is best set to 1. Experiment with this parameter to determine the best configuration.

Examples

In the following example, the software is configured to receive up to seven frames before it must send an acknowledgment. Seven frames is the maximum allowed by Systems Network Architecture (SNA) before a reply must be received:

! enter a global command, if you have not already

interface tokenring 0

! receive up to seven frames before sending an acknowledgment

 llc2 ack-max 7

! sample delay-time command

 llc2 ack-delay-time 100

Related Commands

llc2 adm-timer-value

To control the amount of time the Cisco IOS software waits for, in Asynchronous Disconnect Mode (ADM) before giving up, use the llc2 adm-timer-value command in interface configuration mode. To restore the default configuration, use the no form of this command.

llc2 adm-timer-value milliseconds

no llc2 adm-timer-value milliseconds

Syntax Description

Command Default

The default is 60000 ms.

Command Modes

Interface configuration

Command History

Usage Guidelines

The command llc2 adm-timer-value command is used to clear out the Logical Link Control (LLC) sessions that are left in the ADM State for a defined time period, so that the router does not hang.

Examples

This example shows how to control the waiting time with the llc2 adm-timer-value command:

Router (config-if)# llc2 adm-timer-value 3

Related Commands

llc2 dynwind

To enable dynamic window congestion management, use the llc2 dynwind command in interface configuration mode. To cancel the configuration, use the no form of this command.

llc2 dynwind [nw nw-number] [dwc dwc-number]

no llc2 dynwind [nw nw-number] [dwc dwc-number]

Syntax Description

Defaults

The default nw-number value is 4.
The default dwc-number value is 1.

Command Modes

Interface configuration

Command History

Examples

The following example specifies that to increment the working window six frames must be received, and the working window value should be set to 1 when BECN occurs:

llc2 dynwind nw 6 dwc 1

llc2 idle-time

To control the frequency of polls during periods of idle time (no traffic), use the llc2 idle-time command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 idle-time milliseconds

no llc2 idle-time milliseconds

Syntax Description

Defaults

10000 ms

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

Periodically, when no information frames are being sent during an LLC2 session, LLC2 stations are sent a Receiver Ready frame to indicate that they are available. Set the value for this command low enough to ensure a timely discovery of available stations, but not too low, or you will create a network overhead with too many Receiver Ready frames.

Examples

In the following example, the Cisco IOS software waits 20,000 ms before sending a Receiver Ready ("are you there") frame:

! enter a global command, if you have not already 
interface tokenring 0

! wait 20000 milliseconds before sending receiver-ready frames

 llc2 idle-time 20000 

Related Commands

llc2 local-window

To control the maximum number of information frames the Cisco IOS software sends before it waits for an acknowledgment, use the llc2 local-window command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 local-window packet-count

no llc2 local-window packet-count

Syntax Description

Defaults

Seven packets.

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

An Logical Link Control, type 2 (LLC2)-speaking station can send only a predetermined number of frames before it must wait for an acknowledgment from the receiver. Set this number to the maximum value that can be supported by the stations with which the router communicates. Setting this value too large can cause frames to be lost, because the receiving station may not be able to receive all of them.

Examples

In the following example, the software will send as many as 30 information frames through Token Ring interface 1 before it must receive an acknowledgment:

! enter a global command, if you have not already

interface tokenring 1

 llc2 local-window 30 

Related Commands

llc2 n1

To specify the maximum size of an I-frame, use the llc2 n1 command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 n1 bytes

no llc2 n1

Syntax Description

Defaults

The default maximum I-frame size is 4105 bytes.

Command Modes

Internal adapter configuration

Command History

Examples

The following example sets the maximum I-frame size to 2057 bytes:

! enter a global command, if you have not already

interface tokenring 1

! maximum I-frame size of 2057 bytes

 llc2 n1 2057

Related Commands

llc2 n2

To control the amount of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations, use the llc2 n2 command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 n2 retry-count

no llc2 n2

Syntax Description

Defaults

Eight retries

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

An Logical Link Control, type 2 (LLC2) station must have some limit to the number of times it will resend a frame when the receiver of that frame has not acknowledged it. After the software is told that a remote station is busy, it will poll again based on the retry-count value. When this retry count is exceeded, the LLC2 station terminates its session with the other station. Set this parameter to a value that balances between frame checking and network performance.

Examples

In the following example, the software will resend a frame up to four times through Token Ring interface 1 before it must receive an acknowledgment. Because you generally do not need to change the retry limit, this example shows you how to reset the limit to the default of 8.

! enter a global command, if you have not already

interface tokenring 1

! retry value of 8 

 llc2 n2 8 

Related Commands

llc2 nw

To increase the window size for consecutive good I-frames received, use the llc2 nw internal adapter configuration command. To revert to the default setting, use the no form of this command.

llc2 nw window-size-increase

no llc2 nw

Syntax Description

Defaults

0 (disabled).

Command Modes

Internal adapter configuration

Command History

Examples

In the following example, the window size for Token Ring interface 1 is increased by 1 frame when consecutive good I-frames are received:

! enter a global command, if you have not already

interface tokenring 1

! increase window size by 1

 llc2 nw 1

Related Commands

llc2 recv-window

To control the number of frames in the receive window, use the llc2 recv-window command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 recv-window frame-count

no llc2 recv-window

Syntax Description

Defaults

Seven frames.

Command Modes

Internal adapter configuration

Command History

Examples

In the following example, the receive window for Token Ring interface 1 contains 11 frames:

! enter a global command, if you have not already

interface tokenring 1

! 11 frames in the receive window

 llc2 recv-window 11

Related Commands

llc2 rnr-activated

To invoke dynamic windowing logic for a link station when the router receives an RNR from the remote link station, use the llc2 rnr-activated internal adapter configuration command. To disable dynamic windowing logic, use the no form of this command.

llc2 rnr-activated

no llc2 rnr-activated

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled.

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

The llc2 nw command must be enabled before the llc2 rnr-activated command can be configured.

Examples

In the following example, the llc2n rnr-activated command is enabled on Adapter 0 4000.cafe.0000:

interface Channel4/2

 max-llc2-rcvbuffs 750

lan TokenRing 12

 source-bridge 16 1 500

 adapter 0 4000.cafe.0000

  llc2 Nw 31

  llc2 rnr-activated

 adapter 1 4000.cafe.0001

Related Commands

llc2 send-window

To control the number of frames in the send window, use the llc2 send-window command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 send-window frame-count

no llc2 send-window

Syntax Description

Defaults

Seven frames.

Command Modes

Internal adapter configuration

Command History

Examples

In the following example, the send window for Token Ring interface 1 contains 11 frames:

! enter a global command, if you have not already

interface tokenring 1

! 11 frames in the send window

 llc2 send-window 11

Related Commands

llc2 t1-time

To control the amount of time the Cisco IOS software will wait before resending unacknowledged information frames, use the llc2 t1-time command in internal adapter configuration mode. To revert to the default setting, use the no form of this command.

llc2 t1-time milliseconds

no llc2 t1-time milliseconds

Syntax Description

Defaults

1000 ms.

Command Modes

Internal adapter configuration

Command History

Usage Guidelines

Use this command in conjunction with the llc2 n2 command to provide a balance of network monitoring and performance. Ensure that enough time is allowed to account for the round trip between the router and its Logical Link Control, type 2 (LLC2)-speaking stations under heavy network loading conditions.

Examples

In the following example, the software will wait 4000 ms before resending an unacknowledged frame through Token Ring interface 2:

! enter a global command, if you have not already

interface tokenring 2

! wait 4000 milliseconds before retransmitting a frame through tokenring 2

 llc2 t1-time 4000

Related Commands