Tag :: Segment Routing

The BGP-LS extension allows IGPs (OSPF/IS-IS) link state database information to be injected into BGP. This is typically used in deployments where some external component, (like a controller or Path Computation Engine) can do centralized path computations by learning the entire IGP topology through BGP-LS. The controller can then communicate the computed paths based on the BGP-LS updates to the head end device in the network. The mechanism used by the controller to communicate the computed TE paths is outside the scope of this document. Using BGP-LS instead of an IGP peering with the controller to distribute IGP link state information has the following advantages.

This feature introduces a way for IS-IS to advertise its IP reachability and SID for loopback interfaces only when routes matching an RCF function are present. One example use-case is to use IS-IS Segment Routing to attract traffic to a router only when routes towards the ultimate destination are present.

Segment Routing provides mechanism to define end-to-end paths within a topology by encoding paths as sequences of sub-paths or instructions. These sub-paths or instructions are referred to as “segments”. IS-IS Segment Routing (henceforth referred to as IS-IS SR) provides means to advertise such segments through IS-IS protocol.

This feature allows a user to configure multiple static adjacency SIDs for an IS IS adjacency. This feature is an

Routing Control Functions (RCF) is a language that can express route filtering and attribute modification logic in a powerful and programmatic fashion.The document covers: Configurations of a RCF function for BGP points of application

Bidirectional Forwarding Detection (BFD) is a protocol that provides low-overhead, short-duration detection of failures of arbitrary paths between two systems.

Segment Routing Traffic Engineering Policy (SR TE) aka SR Policy makes use of Segment Routing (SR) to allow a headend

Segment Routing Traffic Engineering Policy (SR TE) aka SR Policy makes use of Segment Routing (SR) to allow a headend

Segment Routing provides a mechanism to define end-to-end paths within a topology by encoding paths as sequences of sub-paths or instructions. These sub-paths or instructions are referred to as “segments”. OSPF Segment Routing (henceforth referred to as OSPF SR) provides means to advertise such segments through OSPF protocol.

Topology Independent Fast Reroute, or TI-LFA, uses IS-IS SR to build loop-free alternate paths along the post-convergence path. These loop-free alternates provide fast convergence.