Configure Optional IS-IS Global Parameters

Use the following procedure to configure optional IS-IS global parameters.

Procedure

  1. Enter IS-IS Router Configuration mode:

    enable

    configure terminal

    router isis

  2. Configure optional IS-IS global parameters:
    1. Specify the Complete Sequence Number Packet (CSNP) interval in seconds:

      csnp-interval <1–600>

    2. Configure the router type globally:

      is-type {l1|l12}

    3. Configure the maximum level, in seconds, between generated LSPs by this Intermediate System:

      max-lsp-gen-interval <30–900>

    4. Configure the IS-IS metric type:

      metric {narrow|wide}

    5. Set or clear the overload condition:

      overload

    6. Configure the overload-on-startup value in seconds:

      overload-on-startup <15–3600>

    7. Configure the Partial Sequence Number Packet (PSNP) in seconds:

      psnp-interval <1–120>

    8. Configure the minimum time between retransmission of an LSP:

      retransmit-lsp-interval <1–300>

    9. Configure the SPF delay in milliseconds:

      spf-delay <0–5000>

    10. Configure the name for the system:

      sys-name WORD<0–255>

    11. Configure the IS-IS system ID for the switch:

      system-id <xxxx.xxxx.xxxx>

Example

Switch> enable

Switch# configure terminal

Switch(config)# router isis

Switch(config-isis)# csnp-interval 10

Switch(config-isis)# is-type l1

Switch(config-isis)# max-lsp-gen-interval 800

Switch(config-isis)# metric wide

Switch(config-isis)# overload

Switch(config-isis)# overload-on-startup 30

Switch(config-isis)# psnp-interval 10

Switch(config-isis)# retransmit-lsp-interval 10

Switch(config-isis)# default sys-name

Switch(config-isis)# spf-delay 200

Switch(config-isis)# default system-id

Variable definitions

The following table defines parameters for the csnp-interval command.

Variable

Value

<1–600>

Specifies the CSNP interval in seconds. This is a system level parameter that applies for level 1 CSNP generation on all interfaces. A longer interval reduces overhead, while a shorter interval speeds up convergence.

The default value is 10. Use the no or default options to set this parameter to the default value of 10.

The following table defines parameters for the is-type command.

Variable

Value

{l1|l12}

Sets the router type globally:

  • l1: Level-1 router type

  • l12: Not valid.

The default value is l1. Use the no or default options to set this parameter to the default value of l1.

The following table defines parameters for the max-lsp-gen-interval command.

Variable

Value

<30–900>

Specifies the maximum interval, in seconds, between generated LSPs by this Intermediate System.

The default value is 900 seconds. Use the no or default options to set this parameter to the default value of 900.

The following table defines parameters for the metric command.

Variable

Value

{narrow|wide}

Specifies the IS-IS metric type. Only wide is supported.

The default value is wide. Use the no or default options to set this parameter to the default value of wide.

The following table defines parameters for the overload command.

Variable

Value

overload

Sets or clears the overload condition.

The default value is disabled. Use the no or default options to set this parameter to the default value of disabled.

The following table defines parameters for the overload-on-startup command.

Variable

Value

<15–3600>

Specifies the IS-IS overload-on-startup value in seconds. The overload-on-startup value is used as a timer to control when to send out LSPs with the overload bit cleared after IS-IS startup.

The default value is 20. Use the no or default options to set this parameter to the default value of 20.

The following table defines parameters for the psnp-interval command.

Variable

Value

<1–120>

Specifies the PSNP interval in seconds. This is a system level parameter that applies for level 1 PSNP generation on all interfaces. A longer interval reduces overhead, while a shorter interval speeds up convergence.

The default value is 2. Use the no or default options to set this parameter to the default value of 2.

The following table defines parameters for the retransmit-lsp-interval command.

Variable

Value

<1–300>

Specifies the minimum time between retransmission of an LSP. This defines how fast the switch resends the same LSP. This is a system level parameter that applies for Level1 retransmission of LSPs.

The default value is 5 seconds. Use the no or default options to set this parameter to the default value of 5.

The following table defines parameters for the spf-delay command.

Variable

Value

<0–5000>

Configures the delay, in milliseconds, to pace successive Shortest Path First (SPF) runs. The timer prevents more than two SPF runs from being scheduled back-to-back. The mechanism for pacing SPF allows two back-to-back SPF runs.

The default value is 100 milliseconds. Use the no or default options to set this parameter to the default value of 100 milliseconds.

The following table defines parameters for the sys-name command.

Variable

Value

WORD<0–255>

Specifies the IS-IS system name. This may be used as the host name for dynamic host name exchange in accordance with RFC 2763.

By default, the system uses the global system name as the IS-IS system name, until you manually configure it. Also, the system does not save the global system name in the running configuration on the switch.

Note:

The system does not display any consistency checks when you edit sys-name.

The following table defines parameters for the system-id command.

Variable

Value

<xxxx.xxxx.xxxx>

Specifies the IS-IS system ID for the switch.

Use the no or default options to set this parameter to the default value (node BMAC).

Job aid

Important

Important

After you have configured the SPBM nickname and enabled IS-IS. To maintain the same nickname with a different system ID, perform the following steps:

  1. Disable IS-IS.

  2. Change the system ID.

  3. Change the nickname to a temporary one.

  4. Enable IS-IS.

  5. Wait up to 20 minutes for the LSPs with the original system ID to age out.

    Note

    Note

    To check the age out time, use the show isis lsdb sysid <original-sys-id> command on any of the other SPB nodes in the network. When there is no output from this command, proceed to the next step. The time left (in seconds) for the LSPs to age out is shown under the column LIFETIME.

  6. Disable IS-IS.

  7. Change the nickname to the original nickname.

  8. Enable IS-IS.