Routing Policies
ExtremeWare XOS 11.3 Concepts Guide
281
Autonomous system expressions. The AS-path keyword uses a regular expression string to match against
the autonomous system (AS) path. Table 37 lists the regular expressions that can be used in the match
conditions for Border Gateway Path (BGP) AS path and community. Table 38 shows examples of regular
expressions and the AS paths they match.
community [no-advertise | no-export | no-export-
subconfed | number <community_num> |
<community_regular_expression> |
<as_num> : <num>];
Where no-advertise, no-export and no-export-subconfed are
the standard communities defined by RFC.
<community_num> is a four byte unsigned integer,
<as_num> is a two byte AS-Number and <num> is the 2-
bytes community number.
Community regular expression is a multi-character regular
expression (with four byte unsigned integer being an
Atom). Regular expression is enclosed in double quotes
("").
med <number>; Where <number> is a 4-byte unsigned integer.
next-hop [<ipaddress> | <ipaddress-regular-
expression>];
Where <ipaddress> is a valid IP address in dotted decimal
format.
nlri [<ipaddress> | any]/<mask-length> {exact};
nlri [<ipaddress> | any] mask <mask> {exact};
Where <ipaddress> and <mask> are IP addresses, <mask-
length> is an integer, and keyword any matches any IP
address with a given (or larger) mask/mask-length.
origin [igp | egp | incomplete]; Where igp, egp and incomplete are the Border Gateway
Protocol (BGP) route origin values.
tag <number>; Where <number> is a 4-byte unsigned 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-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 37: 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
Table 36: Policy match conditions (Continued)
Match Condition Description
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