You can configure an independent autonomous system (AS) domain that is separate from the primary routing instance domain. An AS is a set of routers that are under a single technical administration and that generally use a single IGP and metrics to propagate routing information within the set of routers. An AS appears to other ASs to have a single, coherent interior routing plan and presents a consistent picture of what destinations are reachable through it.
Configuring an independent domain allows you to keep the AS paths of the independent domain from being shared with the AS path and AS path attributes of other domains, including the master routing instance domain.
If you are using BGP on the router, you must configure an AS number.
To configure an independent domain, include the independent-domain statement:
For a list of hierarchy levels at which you can include this statement, see the statement summary section for this statement.
There is a limit of 16 ASs for each domain.