Cisco Nexus 3000 series - Configuring BGP Next-Hop Address Tracking; Configuring Next-Hop Filtering; Disabling Capabilities Negotiation

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release5.0(3)U1(1)
Chapter 6 Configuring Advanced BGP
Configuring Advanced BGP
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:
Configuring Next-Hop Filtering
BGP next-hop filtering allows you to specify that when a next-hop address is checked with the RIB, the
underlying route for that next-hop address is passed through the route map. If the route map rejects the
route, the next-hop address is treated as unreachable.
BGP marks all next hops that are rejected by the route policy as invalid and does not calculate the best
path for the routes that use the invalid next-hop address.
To configure BGP next-hop filtering, use the following command in address-family configuration mode:
Disabling Capabilities Negotiation
You can disable capabilities negotiations to interoperate with older BGP peers that do not support
capabilities negotiation.
To disable capabilities negotiation, use the following command in neighbor configuration mode:
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.
Command Purpose
nexthop route-map name
Example:
switch(config-router-af)# nexthop
route-map nextHopLimits
Specifies a route map to match the BGP next-hop
route to. The name can be any case-sensitive,
alphanumeric string up to 63 characters.