Administrator Guide

neighbor [ip-address | peer-group-name] activate
Congure IPv6 NH Automatically for IPv6 Prex Advertised
over IPv4 Neighbor
You can congure the system to pick the next hop IPv6 address dynamically for IPv6 prex advertised over an IPv4 neighbor. If there is no
IPv6 address congured on the local interface, the system uses the IPv4 mapped IPv6 address. If there are multiple IPv6 addresses
congured on the interface, the system uses the lowest IPv6 address congured on that interface. If the conguration is already present
and a new IPv6 address, which is lower than the lowest existing address, is assigned to one of the peer interfaces, that address is not used
as the NH until you ap the interface manually.
To enable BGP to pick the next hop IPv6 address automatically for IPv6 prex advertised over an IPv4 neighbor, follow this procedure:
• Enable the system to pick the next hop IPv6 address dynamically for IPv6 prex advertised over an IPv4 neighbor.
ROUTER-BGP mode mode
neighbor {neighbor-ipv6–address | peer-group name} auto-local-address
Enter either the neighbor IPv6 address or the name of the peer group.
BGP Regular Expression Optimization
The system optimizes processing time when using regular expressions by caching and re-using regular expression evaluated results, at the
expense of some memory in RP1 processor.
BGP policies that contain regular expressions to match against as-paths and communities might take a lot of CPU processing time, thus
aect BGP routing convergence. Also, show bgp commands that get ltered through regular expressions can to take a lot of CPU cycles,
especially when the database is large.
This feature is turned on by default. If necessary, use the bgp regex-eval-optz-disable command in CONFIGURATION ROUTER
BGP mode to disable it.
Debugging BGP
To enable BGP debugging, use any of the following commands.
• View all information about BGP, including BGP events, keepalives, notications, and updates.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] [in | out]
• View information about BGP route being dampened.
EXEC Privilege mode
debug ip bgp dampening [in | out]
• View information about local BGP state changes and other BGP events.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] events [in | out]
• View information about BGP KEEPALIVE messages.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] keepalive [in | out]
• View information about BGP notications received from or sent to neighbors.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] notifications [in | out]
Border Gateway Protocol IPv4 (BGPv4)
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