Basic IS-IS configuration

For IS-IS to operate on the routers, IS-IS must be explicitly enabled, and at least one area address and interface must be configured. If IS-IS is enabled but no area address or interface is defined, the protocol is enabled but no routes are exchanged. When at least one area address and interface are configured, then adjacencies can be formed and routes exchanged.

To configure IS-IS, perform the following steps.
  1. Enable IS-IS (specifying the instance ID of multi-instance IS-IS is to be enabled).

  2. Modify the level capability, if necessary, on the global level (default is level-1/2).

  3. Define area addresses.

  4. Configure IS-IS interfaces.

The following output displays IS-IS default values.

*A:Dut-D>config>router>isis# info detail
----------------------------------------------
           no system-id
           no router-id
           level-capability level-1/2
           no graceful-restart
           no auth-keychain
           no authentication-key
           no authentication-type
           authentication-check
           csnp-authentication
           no ignore-lsp-errors
           no ignore-narrow-metric
           lsp-lifetime 1200
           lsp-mtu-size 1492
           lsp-refresh-interval 600
           no export-limit
           no export
           no import
           hello-authentication
           psnp-authentication
           no traffic-engineering
           no reference-bandwidth   
           no default-route-tag
           no disable-ldp-sync
           no advertise-passive-only
           no advertise-router-capability
           no hello-padding
           no ldp-over-rsvp
           no advertise-tunnel-link
           no ignore-attached-bit
           no suppress-attached-bit
           no iid-tlv-enable
           no poi-tlv-enable
           no prefix-limit
           no loopfree-alternates
           no rib-priority high
           ipv4-routing
           no ipv6-routing
           ipv4-multicast-routing native
           ipv6-multicast-routing native
           no multi-topology
           no unicast-import-disable both
           no multicast-import both
           no strict-adjacency-check
           igp-shortcut
               shutdown
               tunnel-next-hop
                   family ipv4
                       resolution disabled
                       resolution-filter
                           no rsvp
                           no sr-te
                   exit
                   family ipv6
                       resolution disabled
                       resolution-filter
                           no rsvp
                           no sr-te
                   exit
                   family srv4
                       resolution disabled
                       resolution-filter
                           no rsvp
                           no sr-te
                   exit
                   family srv6
                       resolution disabled
                       resolution-filter
                           no rsvp
                           no sr-te
                   exit
               exit
           exit
           timers
               lsp-wait 5000 lsp-initial-wait 10 lsp-second-wait 1000
               sfp-wait 10000 sfp-initial-wait 1000 sfp-second-wait 1000
           exit
           level 1
               advertise-router-capability
               no hello-padding
               no lsp-mtu-size
               no auth-keychain
               no authentication-key
               no authentication-type
               csnp-authentication
               external-preference 160
               hello-authentication
               no loopfree-alternate-exclude
               preference 15
               psnp-authentication
               no wide-metrics-only
               default-metric 10
              default-ipv4-multicast-metric 10
               default-ipv6-unicast-metric 10
               default-ipv6-multicast-metric 10
           exit
           level 2
               advertise-router-capability
               no hello-padding
               no lsp-mtu-size
               no auth-keychain
               no authentication-key
               no authentication-type
               csnp-authentication
               external-preference 165
              hello-authentication
               no loopfree-alternate-exclude
               preference 18
               psnp-authentication
               no wide-metrics-only
               default-metric 10
               default-ipv4-multicast-metric 10
               default-ipv6-unicast-metric 10
               default-ipv6-multicast-metric 10
           exit                     
           segment-routing
               shutdown
               adj-sid-hold 15
               no export-tunnel-table
               no prefix-sid-range
               no tunnel-table-pref
               no tunnel-mtu
               mapping-server
                   shutdown
               exit
           exit
           no shutdown