Extreme Networks ExtremeWare XOS 11.1, Manual

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Routing Policies
ExtremeWare XOS 11.1 Concepts Guide
193
Autonomous system expressions. The
AS-path
keyword uses a regular expression string to match against
the autonomous system (AS) path. Table 27 lists the regular expressions that can be used in the match
conditions for Border Gateway Path (BGP) AS path and community. Table 28 shows examples of regular
expressions and the AS paths they match.
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-extern1 | ospf-extern2 | 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 27: AS 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 28: 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
Path that starts with 99 followed by 34 “^99 34 “ 99 34 45
Path that ends with 99 “99 $” 45 66 99
Table 26: Policy match conditions (Continued)
Match Condition Description