neighbor 100.100.100.100 no shutdownDell#Configuring Passive PeeringWhen you enable a peer-group, the software sends an OPEN message to initiate a TCP connection.If you enable passive peering for the peer group, the software does not send an OPEN message, but it responds to an OPEN message.When a BGP neighbor connection with authentication configured is rejected by a passive peer-group, Dell Networking OS does not allowanother passive peer-group on the same subnet to connect with the BGP neighbor. To work around this, change the BGP configuration orchange the order of the peer group configuration.You can constrain the number of passive sessions accepted by the neighbor. The limit keyword allows you to set the total number ofsessions the neighbor will accept, between 2 and 265. The default is 256 sessions.1 Configure a peer group that does not initiate TCP connections with other peers.CONFIG-ROUTER-BGP modeneighbor peer-group-name peer-group passive limitEnter the limit keyword to restrict the number of sessions accepted.2 Assign a subnet to the peer group.CONFIG-ROUTER-BGP modeneighbor peer-group-name subnet subnet-number maskThe peer group responds to OPEN messages sent on this subnet.3 Enable the peer group.CONFIG-ROUTER-BGP modeneighbor peer-group-name no shutdown4 Create and specify a remote peer for BGP neighbor.CONFIG-ROUTER-BGP modeneighbor peer-group-name remote-as as-numberOnly after the peer group responds to an OPEN message sent on the subnet does its BGP state change to ESTABLISHED. After the peergroup is ESTABLISHED, the peer group is the same as any other peer group.For more information about peer groups, refer to Configure Peer Groups.Maintaining Existing AS Numbers During an AS MigrationThe local-as feature smooths out the BGP network migration operation and allows you to maintain existing ASNs during a BGP networkmigration.When you complete your migration, be sure to reconfigure your routers with the new information and disable this feature.• Allow external routes from this neighbor.CONFIG-ROUTERBGP modeneighbor {IP address | peer-group-name local-as as number [no prepend]• Peer Group Name: 16 characters.• AS-number: 0 to 65535 (2-Byte) or 1 to 4294967295 (4-Byte) or 0.1 to 65535.65535 (Dotted format).Border Gateway Protocol IPv4 (BGPv4) 201
