Chapter 29. Border Gateway Protocol - Lenovo CN4093 Application Manual

Chapter 29. Border Gateway Protocol

© Copyright Lenovo 2015
Border Gateway Protocol (BGP) is an Internet protocol that enables routers on an
IPv4 network to share and advertise routing information with each other about the
segments of the IPv4 address space they can access within their network and with
routers on external networks. BGP allows you to decide what is the "best" route for
a packet to take from your network to a destination on another network rather than
simply setting a default route from your border router(s) to your upstream
provider(s). BGP is defined in RFC 1771.
CN4093 10Gb Converged Scalable Switches (CN4093s) can advertise their IP
interfaces and IPv4 addresses using BGP and take BGP feeds from as many as BGP
router peers. This allows more resilience and flexibility in balancing traffic from
the Internet.
Note: Lenovo N/OS 8.3 does not support IPv6 for BGP.
The following topics are discussed in this section:
 "Internal Routing Versus External Routing" on page 434
 "Forming BGP Peer Routers" on page 435
 "What is a Route Map?" on page 436
 "Aggregating Routes" on page 439
 "Redistributing Routes" on page 439
 "BGP Attributes" on page 440
 "Selecting Route Paths in BGP" on page 441
 "BGP Failover Configuration" on page 442
 "Default Redistribution and Route Aggregation Example" on page 444
433