<tag/bgpmask/
BGP masks are patterns used for BGP path matching
- (using <cf>path ˜ /2 3 5 ?/</cf> syntax). The masks
+ (using <cf>path ˜ |2 3 5 *|</cf> syntax). The masks
resemble wildcard patterns as used by UNIX shells. Autonomous
- system numbers match themselves, <cf/?/ matches any (even empty)
- sequence of arbitrary AS numbers (<cf/*/ hasn't been chosen, because
- <cf>/*</cf> starts a comment). For example:
- <tt>/4 3 2 1/ ˜ /? 4 3 ?/</tt> is true, but
- <tt>/4 3 2 1/ ˜ /? 4 5 ?/</tt> is false.
+ system numbers match themselves, <cf/*/ matches any (even empty)
+ sequence of arbitrary AS numbers. For example:
+ <tt>|4 3 2 1| ˜ |? 4 3 *|</tt> is true, but
+ <tt>|4 3 2 1| ˜ |? 4 5 *|</tt> is false.
+ There is also old syntax that uses / instead of | and ? instead of *.
<tag/clist/
Community list is similar to set of pairs,
except that unlike other sets, it can be modified.
bgp_community.add((65000,5678));
# Artificially increase path length
# by advertising local AS number twice
- if bgp_path ~ / 65000 / then
+ if bgp_path ~ | 65000 | then
bgp_path.prepend(65000);
accept;
}