checktheroads-hyperglass/docs/extras/common_as_path_regex.md

Expression	Match
.\*	Anything
.+	One Character
^$	Local Routes
\_65000$	Originated by AS65000
^65000\_	Received from AS65000
_65000_	Via AS65000
_65000_65001_	Via AS65000 and AS65001
_(65000_)+	Multiple AS65000 in path
^[0-9]+$	AS_PATH length of 1
^[0-9]+_[0-9]+$	AS_PATH length of 2
^[0-9]*_[0-9]+$	AS_PATH length of 1 or 2
^[0-9]*_[0-9]*$	AS_PATH length of 0, 1, or 2
^[0-9]+_[0-9]+_[0-9]+$	AS_PATH length of 3
_(65000|65001)_	Anything that has gone through AS65000 or AS65001
_65000(_.+_)65001$	Anything from AS65001 that passed through AS65001