Specifications

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
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Chapter 6 Configuring Advanced BGP
Licensing Requirements for Advanced BGP
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, and one set of routes for IPv4 multicast routing. You can use MP-BGP for
reverse-path forwarding (RPF) checks in IP multicast networks.
Note Because Multicast BGP does not propagate multicast state information, you need a multicast protocol,
such as Protocol Independent Multicast (PIM).
Use the router address-family and neighbor address-family configuration modes to support
multiprotocol BGP configurations. MP-BGP maintains separate RIBs for each configured address
family, such as a unicast RIB and a multicast RIB for BGP.
A multiprotocol BGP network is backward compatible but BGP peers that do not support multiprotocol
extensions cannot forward routing information, such as address family identifier information, that the
multiprotocol extensions carry.
Virtualization Support
Cisco NX-OS supports multiple instances of BGP that run on the same system. BGP supports Virtual
Routing and Forwarding instances (VRFs).
By default, Cisco NX-OS places you in the default VRF unless you specifically configure another VRF.
See Chapter 11, “Configuring Layer 3 Virtualization.”
Licensing Requirements for Advanced BGP
The following table shows the licensing requirements for this feature: