Connectivity Guide

MED 0
Route ap
dampening
parameters
• half-life = 15 minutes
• max-suppress-time = 60 minutes
• reuse = 750
• suppress = 2000
Timers
• keepalive = 60 seconds
• holdtime = 180 seconds
Add-path Disabled
Enable BGP
Before enabling BGP, assign a BGP router ID to the switch using the following command:
• In the ROUTER BGP mode, enter the router-id ip-address command. Where in, ip-address is the IP address corresponding
to a congured L3 interface (physical, loopback, or LAG).
BGP is disabled by default. The system supports one AS number — you must assign an AS number to your device. To establish BGP
sessions and route trac, congure at least one BGP neighbor or peer. In BGP, routers with an established TCP connection are called
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 rst 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, from 1 to 65535 for 2-byte, 1 to 4294967295 for
4-byte. 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 conguration when you change the conguration of a BGP neighbor, use the clear ip bgp * command. To view the BGP
status, use the show ip bgp summary command.
Congure 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)# no shutdown
OS10(config-router-neighbor)# description n1_abcd
OS10(config-router-neighbor)# exit
438
Layer 3