Technical data

System Administration
303561-A Rev 00
8-75
Table 8-9 shows examples of AS path pattern matching using the ip bgp_routes
command with a <simplified_regular_expression>.
^ Following pattern occurs at the beginning of the AS path
$ Preceding pattern occurs at the end of the AS path
| Logical OR operation: Match this or that
_
X
_Exact match = “
X
”
_
X
Matching AS pattern that begins with
X
(for example, ”_99” matches 99
991 9934)
X
_ Matching AS pattern that ends with
X
(for example, “99_” matches 99
199 23299)
Note:
Use the symbols < > and { } only when you want to distinguish between
AS sets and AS sequences.
Table 8-9. Simplified AS Pattern Matching Examples
Command Operation
AS path contains:
ip bgp_routes -R _555_> Match exactly any occurrence of AS 555 inside any
AS SEQUENCE.
ip bgp_routes -R _555_} Match exactly any occurrence of AS 555 inside any
AS SET.
ip bgp_routes -R 555_ Match any AS that begins with 555.
ip bgp_routes -R 555_ Match any sequence that begins with AS 555.
ip bgp_routes -R _555_ Match any occurrence of AS 555 inside either an AS
SEQUENCE or an AS SET.
ip bgp_routes -R <555> Match a sequence containing only 1 AS=555.
ip bgp_routes -R {555} Match a set containing only 1 AS=555.
(continued)
Table 8-8. Simplified AS Pattern Matching Syntax
(continued)
Symbol or
Operator Meaning