Note Inject maps and exist maps will only match a single prefix per route map clause. To inject additional prefixes, you must configure additional route map clauses. If multiple prefixes are used, the first prefix that is matched will be used. BGP Peer Templates To address some of the limitations of peer groups such as configuration management, BGP peer templates were introduced to support the BGP update group configuration. A peer template is a configuration pattern that can be applied to neighbors that share 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 policies. Peer templates also allow the network operator to define 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 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. BGP peer devices using peer templates also benefit from automatic update group configuration.
With the configuration of the BGP peer templates and the support of the BGP dynamic update peer groups, the network operator no longer must configure peer groups in BGP and the network can benefit from improved configuration flexibility and faster convergence. 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. Note The following restrictions apply to the peer policy templates: • A peer policy template can directly or indirectly inherit up to eight peer policy templates.
• 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 only from peer templates. Inheritance in Peer Templates The inheritance capability is a key component of peer template operation. Inheritance in a peer template is similar to node and tree structures that are commonly found in general computing, for example, file and directory trees. A peer template can directly or indirectly inherit the configuration from another peer template. The directly inherited peer template represents the tree in the structure.
The indirectly inherited peer template represents a node in the tree. Because each node also supports inheritance, branches can be created that apply Configuring BGP BGP Peer Templates Configuring BGP 9