IS-IS segment routing

IS-IS segment routing support is enabled through MPLS. Currently, label advertisements are supported for IS-IS only. IS-IS creates an adjacency segment per adjacency, per level, and per address family (one each for IPv4 and IPv6). Junos OS IS-IS implementation allocates node segment label blocks in accordance with the IS-IS protocol extensions for supporting segment routing node segments and provides a mechanism to the network operator to provision an IPv4 or IPv6 address family node segment index. To configure segment routing, use the following configuration statements at the [edit protocols isis] hierarchy level: 

• source-packet-routing-Enable the source packet routing feature. 
• node-segment-Enable source packet routing at all levels. 
• use-source-packet-routing-Enable use of source packet routing node segment labels for computing backup paths for normal IPv4 or IPv6 IS-IS prefixes and primary IS-IS source packet routing node segments. 
• no-advertise-adjacency-segment-Disable advertising of the adjacency segment on all levels for a specific interface.