Hi Alex, I am pretty sure, you will never see the same community twice (unlike AS in AS-PATH). So your regex to match multiple occurrences of a community is not necessary.
On Wednesday, August 24, 2016, Alexander Arseniev <[email protected]> wrote: > Hello, > > JUNOS allows You to use regex with communities > > https://www.juniper.net/techpubs/en_US/junos16.1/topics/usag > e-guidelines/policy-defining-bgp-communities-and-extended- > communities-for-use-in-routing-policy-match-conditions.html > > So if You want to restrict ANY community value to no more than N > occurences, then > > set policy-options community no-more-than-N-only members > "^(.*):(.*){N+1,}$" > > - and matching it in the BGP import policy should do the job. > > And I never tested it myself... > > You may need to construct another regex for extended communities though. > > > HTH > > Thx > > Alex > > > On 23/08/2016 14:04, James Bensley wrote: > >> On 23 August 2016 at 13:40, Olivier Benghozi >> <[email protected]> wrote: >> >>> And about a limitation to 10 communities: >>> I've seen that on SEOS (Redback/Ericsson OS for SmartEdge routers) when >>> using "set community" in a route-map. This is a ridiculous arbitrary >>> limitation, of course. >>> >>> Hopefully the limitation was only in the CLI, not in the BGP code >>> itself. So the workaround was to use the route-map "continue" command like >>> in a BASIC GOTO structure to add more communities in additional route-map >>> entries (with set community additive - these are Cisco-like commands). >>> >>> Le 23 août 2016 à 14:03, Alexander Arseniev <[email protected]> a >>>> écrit : >>>> >>>> In BGP messages, a regular community is encoded in 7 bytes, and >>>> extended one in 11 bytes. >>>> >>>> Max BGP message size is 4096 bytes - this sets a limit for regular >>>> communities number to about 4K/7=570, and for extended communities to about >>>> 4K/11=360, if You consider the minimal mandatory information that has to be >>>> there apart from communities. >>>> >>>> >>>> On 23/08/2016 03:18, Huan Pham wrote: >>>> >>>>> I remember hitting a limit on a number of communities (something like >>>>> 10 or >>>>> so) on a platform (can not remember which one from which vendor). So I >>>>> believe that there is a hard limit a platform or OS can support. >>>>> >>>>> I test this in the lab and found no problem with tagging 100 >>>>> communities. >>>>> >>>>> Is there a maximum number of communities that Junos can tag to a >>>>> route? If >>>>> yes, then what it is? Thanks. >>>>> >>>> >> Hi, >> >> Hopefully not completely hijacking this thread; I'm interested to know >> if there is a way I can limit a peer to a maximum number of >> communities? >> >> >> Cheers, >> James. >> _______________________________________________ >> juniper-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/juniper-nsp >> > > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
