Specifications
122 ExtremeWare XOS 10.1 Concepts Guide
Security
Autonomous System Expressions
The AS-path keyword uses a regular expression string to match against the AS path. Regular espression
notation can include any of the characters listed in Table 24.
route-origin [direct | static | icmp | egp | ggp | hello |
rip | isis | esis | cisco-igrp | ospf | bgp | idrp | dvmrp |
mospf | pim-dm | pim-sm | ospf-intra | ospf-inter |
ospf-as-external | ospf-extern-1 | ospf-extern-2 |
bootp | e-bgp | i-bgp | mbgp | i-mbgp | e-mbgp |
isis-level-1 | isis-level-2 | isis-level-1-external |
isis-level-2-external]
Matches the origin (different from BGP route origin) of a
route.
A match statement "route-origin bgp" will match routes
whose origin are "I-bgp" or "e-bgp" or "I-mbgp" or "e-mbgp".
Similarly, the match statement "route-origin ospf" will
match routes whose origin is "ospf-inta" or "ospf-inter" or
"ospf-as-external" or "ospf-extern-1" or "ospf-extern-2"
Table 24: Autonomous System Regular Expression Notation
Character Definition
N As number
N
1
- N
2
Range of AS numbers, where N
1
and N
2
are AS numbers and N
1
< N
2
[N
x
... N
y
] Group of AS numbers, where N
x
and N
y
are AS numbers or a range of AS numbers
[^N
x
... N
y
] Any AS numbers other than the ones in the group
. Matches any number
^ Matches the beginning of the AS path
$ Matches the end of the AS path
– Matches the beginning or end, or a space
- Separates the beginning and end of a range of numbers
* Matches 0 or more instances
+ Matches 1 or more instances
? Matches 0 or 1 instance
{ Start of AS SET segment in the AS path
} End of AS SET segment in the AS path
( Start of a confederation segment in the AS path
) End of a confederation segment in the AS path
Table 25: Policy Regular Expression Examples
Attribute Regular Expression Example Matches
AS path is 1234 “1234” 1234
Zero or more occurrences
of AS number 1234
“1234*” 1234
1234 1234
Start of As path set “10 12 { 34” 10 12 34 { 99
33 10 12 { 34 37
End of As path set “12 } 34” 12 } 34 56
Table 23: Policy Match Conditions (continued)
Match Condition Description