Alternation: Matching One of a Set of Characters

A bar () is used to specify an OR operation. That is, a literal on one or the other side of the bar can be matched. For example:

  ip as-path access-list 25 permit ^(851   852)$  

This filter matches an AS_PATH in which there is a single AS number, which is either 851 or 852. You may extend the OR function to check for more than two possible matches:

  ip as-path access-list 26 permit ^(851   852   6341   53)$