Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.14.1.0 - Page 195

For the router's identifier, Dell EMC Networking OS uses the highest IP address of the Loopback interfaces configured. Because Loopback interfaces are virtual, they cannot go down, thus preventing changes in the router ID. If you do not configure Loopback interfaces, the highest IP address of any interface is used as the router ID. To view the status of BGP neighbors, use the show ip bgp neighbors command in EXEC Privilege mode as shown in the first example. For BGP neighbor configuration information, use the show running-config bgp command in EXEC Privilege mode as shown in the second example. NOTE: The showconfig command in CONFIGURATION ROUTER BGP mode gives the same information as the show running-config bgp command. The following example displays two neighbors: one is an external internal BGP neighbor and the second one is an internal BGP neighbor. The first line of the output for each neighbor displays the AS number and states whether the link is an external or internal (shown in bold). The third line of the show ip bgp neighbors output contains the BGP State. If anything other than ESTABLISHED is listed, the neighbor is not exchanging information and routes. For more information about using the show ip bgp neighbors command, refer to the Dell EMC Networking OS Command Line Interface Reference Guide. The following example shows the show ip bgp neighbors command output. DellEMC#show ip bgp neighbors BGP neighbor is 20.20.20.1, remote AS 200, external link BGP remote router ID 1.1.1.1 BGP state ESTABLISHED, in this state for 00:05:22 Last read 00:00:00, Last write 00:00:07 Hold time is 90, keepalive interval is 30 seconds Received 18 messages, 0 in queue 7 opens, 6 notifications, 0 updates 5 keepalives, 0 route refresh requests Sent 26 messages, 0 in queue 7 opens, 0 notifications, 0 updates 19 keepalives, 0 route refresh requests Route refresh request: received 0, sent messages 0 Minimum time between advertisement runs is 30 seconds Minimum time before advertisements start is 0 seconds For address family: IPv4 Unicast BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0 InQ : Added 0, Replaced 0, Withdrawn 0 OutQ : Added 0, Withdrawn 0 Allow local AS number 0 times in AS-PATH attribute Prefixes accepted 0, withdrawn 0 by peer, martian prefixes ignored 0 Prefixes advertised 0, denied 0, withdrawn 0 from peer Connections established 0; dropped 0 Last reset never No active TCP connection Configuring AS4 Number Representations Enable one type of AS number representation: ASPLAIN, ASDOT+, or ASDOT. Term Description ASPLAIN Default method for AS number representation. With the ASPLAIN notation, a 32-bit binary AS number is translated into a decimal value. ASDOT+ A representation splits the full binary 4-byte AS number into two words of 16 bits separated by a decimal point (.): .. Border Gateway Protocol version 4 (BGPv4) 195