Cisco Cisco IOS Software Release 12.0(24)S

The introduction of the BGP Dynamic Update Peer-Groups feature separates peer-group configuration 
from update group generation. The BGP Dynamic Update Peer-Groups feature introduced an algorithm 
that dynamically calculates BGP update-group membership based on outbound routing policies. Optimal 
BGP update message generation occurs automatically and independently. BGP neighbor configuration 
is no longer restricted by outbound routing policies, and update-groups can belong to different address 
families. 

Even though BGP update message generation has been separated from peer group configuration, peer 
group configuration still retains the following limitations: 

A neighbor can belong only to one peer group.

Neighbors that belong to different address-families cannot belong to the same peer group.

Different sets of policies cannot be grouped and applied to a neighbor. 

To address the limitations of peer groups, the BGP Configuration Using Peer Templates feature was 
introduced along with the BGP Dynamic Update Peer-Groups feature. The BGP Configuration Using 
Peer Templates feature introduces a new mechanism called the peer template. For more information 
about the BGP Dynamic Update Peer-Groups feature, refer to the 

document. 

A peer template is a configuration pattern that can be applied to neighbors that share common policies. 
Peer templates are reusable and support inheritance, which allows the network operator to group and 
apply distinct neighbor configurations for BGP neighbors that share common policies. Peer templates 
also allow the network operator to define very complex configuration patterns through the capability of 
a peer template to inherit a configuration from another peer template. 

There are two types of peer templates:

Peer session templates are used to group and apply the configuration of general session commands 
that are common to all address family and Network Layer Reachability Information (NLRI) 
configuration modes. 

Peer policy templates are used to group and apply the configuration of commands that are applied 
within specific address-families and NLRI configuration modes. 

Peer templates improve the flexibility and enhance the capability of neighbor configuration. Peer 
templates also provide an alternative to peer group configuration and overcome some limitations of peer 
groups. With the configuration of the BGP Configuration Using Peer Templates feature and the support 
of the BGP Dynamic Update Peer-Groups feature, the network operator no longer needs to configure 
peer groups in BGP and can benefit from improved configuration flexibility and faster convergence.

Peer groups are still supported. The configuration of the BGP Configuration Using Peer Templates 
feature does not conflict with or restrict peer group configuration. However, a BGP neighbor cannot be 
configured to work with both peer groups and peer templates. A BGP neighbor can be configured to 
belong only to a peer group or to inherit policies from peer templates.