BGP Peer Template Overview and Configuration Example

What is BGP Peer Template

BGP peer templates allow you to create blocks of common configuration that you can reuse across similar BGP peers. Each block allows you to define a set of attributes that a peer then inherits.

You can choose to override some of the inherited attributes as well, making it a very flexible scheme for simplifying the repetitive nature of BGP configurations.

There are mainly 2 types of peer templates:

I- Peer-Session Template

The peer-session template defines BGP peer session attributes, such as the transport details, remote autonomous system number of the peer, and session timers.

A peer-session template can also inherit attributes from another peer-session template.

Peer-Session Template configuration Example:

First define the peer-session template and add the needed parameters:

router bgp 65010
 template peer-session LD_TEMP
 remote-as 65020
 local-as 65030
 description LD_TEMPLATECode language: JavaScript (javascript)

We can inherit another peer session template:

router bgp 65010
 template peer-session LD_TEMP
 remote-as 65020
 local-as 65030
 description LD_TEMPLATE
 inherit peer-session LD_GLOBAL_TEMP

template peer-session LD_GLOBAL_TEMP
 update-source Loopback100Code language: JavaScript (javascript)

Apply the session tempalte under the neighbor:

router bgp 65010
 neighbor 172.16.40.2 inherit peer-session LD_TEMPCode language: CSS (css)

II- Peer-Policy Template

A peer-policy template defines the address-family dependent policy aspects for a peer including the inbound and outbound policy, filter-lists, and prefix-lists.

A peer-policy template can inherit from a set of peer-policy templates. 

Peer-Policy Template configuration Example:

router bgp 65010
 template peer-policy ALL_PEERS
  soft-reconfiguration inbound

 template peer-policy eBGP_PEERS
  maximum-prefix 2000
  inherit peer-policy ALL_PEERS 10

 neighbor 172.16.70.2 inherit peer-policy eBGP_PEERSCode language: CSS (css)

Below are the parameters that can defined under Session tempalte and Policy template:

Reference: Cisco.com