• Exchange of IPv4 multicast route information occurs through the use of two new attributes calledMP_REACH_NLRI and MP_UNREACH_NLRI, for feasible and withdrawn routes, respectively.• If the peer has not been activated in any AFI/SAFI, the peer remains in Idle state.Most Dell Networking OS BGP IPv4 unicast commands are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 RIBusing extra options to the command. For a detailed description of the MBGP commands, refer to the DellNetworking OS Command Line Interface Reference Guide.• Enables support for the IPv4 multicast family on the BGP node.CONFIG-ROUTER-BGP modeaddress family ipv4 multicast• Enable IPv4 multicast support on a BGP neighbor/peer group.CONFIG-ROUTER-BGP-AF (Address Family) modeneighbor [ip-address | peer-group-name] activateBGP Regular Expression OptimizationDell Networking OS optimizes processing time when using regular expressions by caching and re-usingregular 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 alot of CPU processing time, thus affect BGP routing convergence. Also, show bgp commands that getfiltered 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 inCONFIGURATION ROUTER BGP mode to disable it.Debugging BGPTo enable BGP debugging, use any of the following commands.• View all information about BGP, including BGP events, keepalives, notifications, and updates.EXEC Privilege modedebug ip bgp [ip-address | peer-group peer-group-name] [in | out]• View information about BGP route being dampened.EXEC Privilege modedebug ip bgp dampening [in | out]• View information about local BGP state changes and other BGP events.EXEC Privilege modedebug ip bgp [ip-address | peer-group peer-group-name] events [in | out]• View information about BGP KEEPALIVE messages.EXEC Privilege modedebug ip bgp [ip-address | peer-group peer-group-name] keepalive [in | out]• View information about BGP notifications received from or sent to neighbors.EXEC Privilege modeBorder Gateway Protocol IPv4 (BGPv4) 211
