Route Redistribution; Tuning Bgp; Bgp Timers; Tuning The Best-Path Algorithm - Cisco Nexus 7000 Series Configuration Manual

Chapter 11 Configuring Advanced BGP
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
Critical and non-critical events can be configured individually on a per address family basis.
Note

Route Redistribution

You can configure BGP to redistribute static routes or routes from other protocols.. You must configure
a route map with the redistribution to control which routes are passed into BGP. A route map allows you
to filter routes based on attributes such as the destination, origination protocol, route type, route tag, and
so on. See
When you redistribute BGP to IGP, iBGP is redistributed as well. To override this behavior, you must
Note
insert an additional deny statement into the route map.

Tuning BGP

You can modify the default behavior of BGP through BGP timers and by adjusting the best-path
algorithm.
This section includes the following topics:
•
•

BGP Timers

BGP uses different types of timers for neighbor session and global protocol events. Each established
session has a minimum of two timers for sending periodic keepalive messages and for timing out
sessions when peer keepalives do not arrive within the expected time. In addition, there are other timers
for handling specific features. Typically, you configure these timers in seconds. The timers include a
random adjustment so that the same timers on different BGP peers trigger at different times.

Tuning the Best-Path Algorithm

You can modify the default behavior of the best-path algorithm through optional configuration
parameters, including changing how the algorithm handles the MED attribute and the router ID.

Multiprotocol BGP

BGP on Cisco NX-OS supports multiple address families. Multiprotocol BGP (MP-BGP) carries
different sets of routes depending on the address family. For example, BGP can carry one set of routes
for IPv4 unicast routing, one set of routes for IPv4 multicast routing, and one set of routes for IPv6
multicast routing. You can use MP-BGP for reverse-path forwarding (RPF) checks in IP multicast
networks.
Because Multicast BGP does not propagate multicast state information, you need a multicast protocol,
Note
such as Protocol Independent Multicast (PIM).
OL-20002-02
Chapter 16, "Configuring Route Policy Manager,"
BGP Timers, page 11-9
Tuning the Best-Path Algorithm, page 11-9
Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
Information About Advanced BGP
for more information.
11-9