Configure Ipv6 Nh Automatically For Ipv6 Prefix Advertised Over Ipv4 Neighbor; Bgp Regular Expression Optimization; Debugging Bgp - Dell S4048–ON Configuration Manual

• If the peer has not been activated in any AFI/SAFI, the peer remains in Idle state.
Most Dell Networking OS BGP IPv4 unicast commands are extended to support the IPv4 multicast RIB using extra options to the
command. For a detailed description of the MBGP commands, refer to the Dell Networking OS Command Line Interface Reference Guide.
• Enables support for the IPv4 multicast family on the BGP node.
CONFIG-ROUTER-BGP mode
address family ipv4 multicast
• Enable IPv4 multicast support on a BGP neighbor/peer group.
CONFIG-ROUTER-BGP-AF (Address Family) mode
neighbor [ip-address | peer-group-name] activate
Configure IPv6 NH Automatically for IPv6 Prefix Advertised
over IPv4 Neighbor
You can configure the system to pick the next hop IPv6 address dynamically for IPv6 prefix advertised over an IPv4 neighbor. If there is no
IPv6 address configured on the local interface, the system uses the IPv4 mapped IPv6 address. If there are multiple IPv6 addresses
configured on the interface, the system uses the lowest IPv6 address configured on that interface. If the configuration 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 flap the interface manually.
To enable BGP to pick the next hop IPv6 address automatically for IPv6 prefix advertised over an IPv4 neighbor, follow this procedure:
• Enable the system to pick the next hop IPv6 address dynamically for IPv6 prefix 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

Dell Networking OS 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
affect BGP routing convergence. Also, show bgp commands that get filtered 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, notifications, 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]
Border Gateway Protocol IPv4 (BGPv4) 225