Extreme Networks ExtremeWare XOS Guide Manual page 122

Security
Table 23: Policy Match Conditions (continued)
Match Condition
nlri [<ipaddress> | any]/<mask-length> {exact};
nlri [<ipaddress> | any] mask <mask> {exact};
origin [igp | egp | incomplete];
tag <number>;
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]
Autonomous System Expressions
The keyword uses a regular expression string to match against the AS path. Table 24 lists the
AS-path
regular expressions that can be used in the match conditions for BGP AS path and community. Table 25
list examples of regular expressions and the AS paths they match.
Table 24: Autonomous System Regular Expression Notation
Character Definition
N As number
N - N Range of AS numbers, where N
1 2
[N ... N ] Group of AS numbers, where N
x y
[^N ... N ] Any AS numbers other than the ones in the group
x y
. 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
AS path is 1234
122
Description
Where, <ipaddress> and <mask> are in dotted decimal
format, <mask-length> is an integer in the range [0 - 32].
Keyword any matches any IP address with a given (or
larger) mask/mask-length.
IGP, EGP and incomplete are the BGP route origin values.
<number> is a four byte unsigned number.
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"
and N
1
and N
x
Regular Expression
"1234"
are AS numbers and N
2 1
are AS numbers or a range of AS numbers
y
Example Matches
1234
< N
2
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