Dell MX9116n EMC SmartFabric OS10 User Guide - Page 531

Passive peering When you enable a peer-template, the system sends an OPEN message to initiate a TCP connection. If you enable passive peering for the peer template, the system does not send an OPEN message but responds to an OPEN message. When a BGP neighbor connection with authentication rejects a passive peer-template, the system prevents another passive peertemplate on the same subnet from connecting with the BGP neighbor. To work around this constraint, change the BGP configuration or change the order of the peer template configuration. You can restrict the number of passive sessions the neighbor accepts using the limit command. 1. Enable BGP and assign the AS number to the local BGP speaker in CONFIGURATION mode (1 to 65535 for 2-byte, 1 to 4294967295 for 4-byte). router bgp as-number 2. Configure a template that does not initiate TCP connections with other peers in ROUTER-BGP mode. A maximum of 16 characters. template template-name 3. Create and enter the AS number for the remote neighbor in ROUTER-BGP-TEMPLATE mode (1 to 4294967295). remote-as as-number 4. Enable peer listening and enter the maximum dynamic peers count in ROUTER-BGP-TEMPLATE mode (1 to 4294967295). listen neighbor ip-address limit Only after the peer template responds to an OPEN message sent on the subnet does the state of its BGP change to ESTABLISHED. After the peer template is ESTABLISHED, the peer template is the same as any other peer template, see Peer templates. If you do not configure a BGP device in Peer-Listening mode, a session with a dynamic peer comes up. Passwords are not supported on BGPv4/v6 dynamic peers. Configure passive peering OS10(config)# router bgp 10 OS10(conf-router-bgp-10)# template bgppg OS10(conf-router-template)# remote-as 100 OS10(conf-router-template)# listen 32.1.0.0/8 limit 10 Local AS During BGP network migration, you can maintain existing AS numbers. Reconfigure your routers with the new information to disable after the migration. Network migration is not supported on passive peer templates. You must configure Peer templates before assigning it to an AS. 1. Enter a neighbor IP address, A.B.C.D, in ROUTER-BGP mode. neighbor ip-address 2. Enter a local-as number for the peer, and the AS values not prepended to announcements from the neighbors in ROUTER-NEIGHBOR mode (1 to 4294967295). local-as as number [no prepend] 3. Return to ROUTER-BGP mode. exit 4. Enter a template name to assign to the peer-groups in ROUTER-BGP mode. A maximum of 16 characters. template template-name 5. Enter a local-as number for the peer in ROUTER-TEMPLATE mode. local-as as number [no prepend] Layer 3 531