the configurations of all indirectly inherited peer templates within a chain back to the directly inherited peer template or the source of the tree. This structure eliminates the need to repeat configuration statements that are commonly reapplied to groups of neighbors because common configuration statements can be applied once and then indirectly inherited by peer templates that are applied to neighbor groups with common configurations. Configuration statements that are duplicated separately within a node and a tree are filtered out at the source of the tree by the directly inherited template.
A directly inherited template overwrites any indirectly inherited statements that are duplicated in the directly inherited template. Inheritance expands the scalability and flexibility of neighbor configuration by allowing you to chain together peer templates configurations to create simple configurations that inherit common configuration statements or complex configurations that apply specific configuration statements along with common inherited configurations. Specific details about configuring inheritance in peer session templates and peer policy templates are provided in the following sections.
When BGP neighbors use inherited peer templates, it can be difficult to determine which policies are associated with a specific template. The detail keyword of the show ip bgp template peer-policy command displays the detailed configuration of local and inherited policies that are associated with a specific template. Peer Session Templates Peer session templates are used to group and apply the configuration of general session commands to groups of neighbors that share session configuration elements. General session commands that are common for neighbors that are configured in different address families can be configured within the same peer session template.
Peer session templates are created and configured in peer session configuration mode. Only general session commands can be configured in a peer session template. The following general session commands are supported by peer session templates: description disable-connected-check ebgp-multihop exit peer-session inherit peer-session local-as password remote-as shutdown timers translate-update update-source version General session commands can be configured once in a peer session template and then applied to many neighbors through the direct application of a peer session template or through indirect inheritance from a peer Configuring BGP Peer Session Templates Configuring BGP 10