Cisco Cisco IOS Software Release 12.2(27)SBC

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The BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO) feature enables provider 
edge (PE) routers to maintain Border Gateway Protocol (BGP) state with customer edge (CE) routers 
and ensure continuous packet forwarding during a Route Processor (RP) switchover or during a planned 
In-Service Software Upgrade (ISSU) for a PE router. CE routers do not need to be Nonstop Forwarding 
(NSF)-capable or NSF-aware to benefit from BGP NSR capabilities on PE routers. Only PE routers need 
to be upgraded to support BGP NSR—no CE router upgrades are required. BGP NSR with SSO, thus, 
enables service providers to provide the benefits NSF with the additional benefits of NSR without 
requiring CE routers to be upgraded to support BGP graceful restart. 

Your Cisco IOS software release may not support all of the features documented in this module. To reach 
links to specific feature documentation in this module and to see a list of the releases in which each feature is 
supported, use the 

.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image 
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