When a caret is used inside a bracket, it negates the range specified in the bracket . As a result, the regex matches on everything except the range. For example: ip as-path access-list 24 permit ^85[^0-5]$ This filter looks like the preceding filter, with the exception of the added caret inside the bracket, signifying "not 0 “5." The regex will therefore match an AS_PATH with a single AS number in the range 856 “859. |