IS-IS Configuration

In order to enable the advertisement of additional link IPv6 and TE parameters, a new traffic-engineering-options CLI construct is used.

configure
     router
          ipv6-te-router-id interface interface-name
          no ipv6-te-router-id
          [no] isis [instance]
               traffic-engineering
               no traffic-engineering
               traffic-engineering-options
               no traffic-engineering-options
                    ipv6
                    no ipv6  
                    application-link-attributes
                    no application-link-attributes
                         legacy
                         no legacy

The existing traffic-engineering command continues its role as the main command for enabling TE in an IS-IS instance. This command enables the advertisement of the IPv4 and TE link parameters using the legacy TE encoding as per RFC 5305. These parameters are used in IPv4 RSVP-TE and IPv4 SR-TE.

When the ipv6 command under the traffic-engineering-options context is also enabled, then the traffic engineering behavior with IPv6 TE links is enabled. This IS-IS instance automatically advertises the new RFC 6119 IPv6 and TE TLVs and sub-TLVs as described in TE Attributes Supported in IGP and BGP-LS.

The application-link-attributes context allows the advertisement of the TE attributes of each link on a per-application basis. Two applications are supported in SRĀ OS: RSVP-TE and SR-TE. The legacy mode of advertising TE attributes that is used in RSVP-TE is still supported but can be disabled by using the no legacy command that enables the per-application TE attribute advertisement for RSVP-TE as well.

Additional details of the feature behavior and the interaction of the previously mentioned CLI commands are described in IS-IS IPv4/IPv6 SR-TE and IPv4 RSVP-TE Feature Behavior.