Configuring the AS Number

An autonomous system (AS) is a set of routers that are under a single technical administration and that generally use a single interior gateway protocol (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.

ASs are identified by a number from 1 through 65,535 that is assigned by the Network Information Center (NIC) in the United States (http://www.isi.edu).

If you are using the Border Gateway Protocol (BGP) on the router, you must configure an AS number.

To configure the router's AS number, include the autonomous-system statement:

[edit]

routing-options {

    autonomous-system autonomous-system <loops number>; 

}

For a list of hierarchy levels at which you can configure this statement, see the statement summary section for this statement.

To specify how many times this AS number can appear in an AS path, include the loops option.