Cisco Cisco CRS-X Multishelf System Release Notes
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Saving the result of different SPF runs in separate databases
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Using these databases to manipulate BGP best path decision and thereby allowing BGP to use and announce best path that is
optimal from the client’s point of view
optimal from the client’s point of view
Enabling the ORR feature increases the memory footprint of BGP and RIB. With increased number of
vRR configured in the network, ORR adversely impacts convergence for BGP.
vRR configured in the network, ORR adversely impacts convergence for BGP.
For more information on BGP ORR, see the Implementing BGP chapter in the Cisco CRS Router Routing
Configuration Guide.
Configuration Guide.
Note
Seamless Bidirectional Forwarding Detection
Bidirectional forwarding detection (BFD) provides low-overhead, short-duration detection of failures in the path between adjacent
forwarding engines. BFD allows a single mechanism to be used for failure detection over any media and at any protocol layer, with
a wide range of detection times and overhead.
forwarding engines. BFD allows a single mechanism to be used for failure detection over any media and at any protocol layer, with
a wide range of detection times and overhead.
In BFD, each end of the connection maintains a BFD state and transmits packets periodically over a forwarding path. Seamless BFD
(SBFD) is unidirectional, resulting in faster session activation. The BFD state and client context is maintained on the head-end
(initiator) only. The tail-end (reflector) validates the BFD packet and responds, so there’s no need to maintain the BFD state on the
tail-end.
(SBFD) is unidirectional, resulting in faster session activation. The BFD state and client context is maintained on the head-end
(initiator) only. The tail-end (reflector) validates the BFD packet and responds, so there’s no need to maintain the BFD state on the
tail-end.
Autoroute Destination
The autoroute destination feature allows you to automatically route traffic through a segment routing tunnel instead of manually
configuring static routes. Static routes are always added with zero-cost metric, which can result in traffic that is mapped on multiple
tunnels to always load-balance due to ECMP. This load-balancing may be undesirable when some of those tunnels have sub-optimal
paths. With autoroute destination, only the tunnel whose IGP cost to its endpoint is lowest will be considered for carrying traffic.
configuring static routes. Static routes are always added with zero-cost metric, which can result in traffic that is mapped on multiple
tunnels to always load-balance due to ECMP. This load-balancing may be undesirable when some of those tunnels have sub-optimal
paths. With autoroute destination, only the tunnel whose IGP cost to its endpoint is lowest will be considered for carrying traffic.
Border Gateway Protocol Link-State
Border gateway protocol link-state (BGP LS) is an Address Family Identifier (AFI) and Sub-address Family Identifier (SAFI) defined
to carry interior gateway protocol (IGP) link-state database through BGP. BGP LS delivers network topology information to topology
servers and Application Layer Traffic Optimization (ALTO) servers. BGP LS supports IS-IS and OSPFv2.
to carry interior gateway protocol (IGP) link-state database through BGP. BGP LS delivers network topology information to topology
servers and Application Layer Traffic Optimization (ALTO) servers. BGP LS supports IS-IS and OSPFv2.
Node and Shared Risk Link Groups Protection with Topology-Independent Loop-Free Alternate
The Topology-Independent Loop-Free Alternate (TI-LFA) node protection functionality provides protection from node failures. The
neighbor node is excluded during the post convergence backup path calculation.
neighbor node is excluded during the post convergence backup path calculation.
The TI-LFA Shared Risk Link Groups (SRLG) protection functionality attempts to find the post-convergence backup path, which
excludes the SRLGs of the protected link. All local links that share any SRLG with the protecting link are excluded during the post
convergence backup path calculation.
excludes the SRLGs of the protected link. All local links that share any SRLG with the protecting link are excluded during the post
convergence backup path calculation.
Segment Routing
Segment routing is a method of forwarding packets on the network based on the source routing paradigm. The source chooses a path
and encodes it in the packet header as an ordered list of segments. Segments are an identifier for any type of instruction. For example,
and encodes it in the packet header as an ordered list of segments. Segments are an identifier for any type of instruction. For example,
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