BGP Essentials: Peer Session Templates

 

Configuring a large number of similar BGP peers on a router and ensuring that the changes in your routing policy or BGP design are applied to all of them can be a management nightmare. BGP peer groups were the only scalability tool available on Cisco IOS until the IOS release 12.3T and they had significant limitations as they were also used as a performance improvement tool.
IOS releases 12.0S and 12.3T introduced peer templates, a scalable hierarchical way of configuring BGP session parameters and inbound/outbound policies. For example, to configure the session parameters for all your IBGP sessions, use the following session template:

router bgp 65001
 template peer-session 
IBGP
  remote-as 65001
  description IBGP peers
  password 
s3cr3t
  update-source Loopback0

After the session template has been configured, adding a new IBGP peer takes just a single configuration command (two if you want to add neighbor description):

router bgp 65001
 neighbor 10.0.1.2 inherit peer-session 
IBGP
 neighbor 10.0.1.2 description R2

If you're looking for more in-depth BGP knowledge, try our Configuring BGP on Cisco Routers e-learning solution. If you just need to enhance your hands-on skill, the BGP Remote Lab Bundle is the perfect choice.

Posted to Cisco IOS Hints and Tricks by IvanPepelnjak
©Copyright Ivan Pepelnjak