Specifications

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
OL-25782-02
Chapter 6 Configuring Advanced BGP
Configuring Advanced BGP
Modifying the Next-Hop Address
You can modify the next-hop address used in a route advertisement in the following ways:
• Disable the next-hop calculation and use the local BGP speaker address as the next-hop address.
• Set the next-hop address as a third-party address. Use this feature in situations where the original
next-hop address is on the same subnet as the peer that the route is being sent to. Using this feature
saves an extra hop during forwarding.
To modify the next-hop address, use the following parameters in commands address-family
configuration mode:
Configuring BGP Next-Hop Address Tracking
BGP next-hop address tracking is enabled by default and cannot be disabled.
You can modify the delay interval between RIB checks to increase the performance of BGP next-hop
tracking. You can configure the critical timer for routes that affect BGP next-hop reachability, and you
can configure the noncritical timer for all other routes in the BGP table.
To modify the BGP next-hop address tracking, use the following commands address-family
configuration mode:
Command Purpose
next-hop-self
Example:
switch(config-router-neighbor-af)#
next-hop-self
Uses the local BGP speaker address as the next-hop
address in route updates. This command triggers an
automatic soft clear or refresh of BGP neighbor
sessions.
next-hop-third-party
Example:
switch(config-router-neighbor-af)#
next-hop-third-party
Sets the next-hop address as a third-party address.
Use this command for single-hop EBGP peers that
do not have next-hop-self configured.
Command Purpose
nexthop trigger-delay {critical |
non-critical} milliseconds
Example:
switch(config-router-af)# nexthop
trigger-delay critical 5000
Specifies the next-hop address tracking delay timer
for critical next-hop reachability routes and for
noncritical routes. The range is from 1 to
4294967295 milliseconds. The critical timer
default is 3000. The noncritical timer default is
10000.
nexthop route-map name
Example:
switch(config-router-af)# nexthop
route-map nextHopLimits
Specifies a route map to match the BGP next-hop
addresses to. The name can be any case-sensitive,
alphanumeric string up to 63 characters.