Templates

Templates hold peer options shared by several peers. A peer uses a template with the template option and inherits every option it doesn't set itself.

templates:
  upstream:
    local-pref: 80
    filter-irr: false

peers:
  Transit A:
    asn: 64496
    template: upstream
    neighbors:
      - 203.0.113.1
  Transit B:
    asn: 64497
    template: upstream
    local-pref: 90 # overrides the template's local-pref
    neighbors:
      - 203.0.113.5

Template inheritance

A template can set a parent template with template. It inherits every option of its parent (and its parent's parents) that it doesn't set itself, so common settings can live in one base template:

templates:
  base:
    filter-transit-asns: true
    add-on-import: [ "65530:0:1" ]
  ix:
    template: base
    local-pref: 110
  ix-rs:
    template: ix
    enforce-first-as: false

Inheritance loops and references to undefined templates are reported as configuration errors.

Merging lists

By default, a list or map option set on a peer replaces the template's value entirely. Set merge-template-lists: true on the peer (or on a template, to apply it to all peers and child templates using it) to merge them instead:

• lists (for example add-on-import, announce or prefixes) are combined, template entries first, and
• map entries (for example community-prefs or as-prefs) are combined, with the peer's entries overriding the template's for the same key.

This allows a peer to add one or two communities to the communities of its exchange's template:

templates:
  ix:
    add-on-import: [ "65530:0:100" ]
    announce: [ "65530:0:10" ]

peers:
  IX Peer:
    asn: 64496
    template: ix
    merge-template-lists: true
    announce: [ "65530:0:20" ] # announces routes tagged 65530:0:10 and 65530:0:20
    neighbors:
      - 198.51.100.2