Dell PowerSwitch S4112F-ON OS10 Enterprise Edition User Guide Release 10.4.1.0 - Page 303

neighbors or peers. After a connection establishes, the neighbors exchange full BGP routing tables with incremental updates afterward. Neighbors also exchange the KEEPALIVE messages to maintain the connection. You can classify BGP neighbor routers or peers as internal or external. Connect EBGP peers directly, unless you enable EBGP multihop - IBGP peers do not need direct connection. The IP address of an EBGP neighbor is usually the IP address of the interface directly connected to the router. The BGP process first determines if all internal BGP peers are reachable, then it determines which peers outside the AS are reachable. 1 Assign an AS number, and enter ROUTER-BGP mode from CONFIGURATION mode (1 to 65535 for 2-byte, 1 to 4294967295 for 4byte). Only one AS number is supported per system. If you enter a 4-byte AS number, 4-byte AS support is enabled automatically. router bgp as-number 2 Enter a neighbor in ROUTER-BGP mode. neighbor ip-address 3 Add a remote AS in ROUTER-NEIGHBOR mode, from 1 to 65535 for 2-byte or 1 to 4294967295 for 4-byte. remote-as as-number 4 Enable the BGP neighbor in ROUTER-NEIGHBOR mode. no shutdown 5 (Optional) Add a description text for the neighbor in ROUTER-NEIGHBOR mode. description text To reset the configuration when you change the configuration of a BGP neighbor, use the clear ip bgp * command. To view the BGP status, use the show ip bgp summary command. Configure BGP OS10# configure terminal OS10(config)# router bgp 100 OS10(config-router-bgp-100)# neighbor 5.1.1.1 OS10(config-router-neighbor)# remote-as 1 OS10(config-router-neighbor)# description n1_abcd OS10(config-router-neighbor)# exit OS10(config-router-bgp-100)# template t1 OS10(config-router-template)# description peer_template_1_abcd View BGP summary with 2-byte AS number OS10# show ip bgp summary BGP router identifier 202.236.164.86 local AS number 64901 Neighbor AS MsgRcvd MsgSent Up/Down State/Pfx 120.10.1.1 64701 664 662 04:47:52 established 12000 View BGP summary with 4-byte AS number OS10# show ip bgp summary BGP router identifier 11.1.1.1, local AS number 4294967295 BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0 1 neighbor(s) using 8192 bytes of memory Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx 5.1.1.2 4294967295 0 0 0 0 0 00:00:00 Active For the router ID, the system selects the first configured IP address or a random number. To view the status of BGP neighbors, use the show ip bgp neighbors command. For BGP neighbor configuration information, use the show running-config bgp command. The example shows two neighbors - one is an external BGP neighbor, and the other is an internal BGP neighbor. The first line of the output for each neighbor displays the AS number and states if the link is external or internal. The third line of the show ip bgp neighbors output contains the BGP state. If anything other than established displays, the neighbor is not exchanging information and routes - see IPv6 commands for more information. Layer 3 303