On 08/09/15 17:15, Job Snijders wrote: > On Tue, Sep 08, 2015 at 05:05:48PM +0200, Randy Bush wrote: >>>> I do not feel comfortable overloading locally administrated bits with >>>> something that represents global significance. The 64xxx communites >>>> come dangerously close to codepoints we use internally. I'd prefer >>>> that the local portion of BGP Communities remains truely local. >>> >>> only problem is that completely blows the purpose of the exercise, a >>> global tagging to help ops and researchers be more sure of what they >>> are seeing in the collectors. >> >> i think i misunderstood you. you are suggesting using 42-44 or >> whatever, not 65000 space. sure. i do not care what the numbers >> are. > > I suggest to take the codepoint(s) from 0xFFFF0000 - 0xFFFFFFFF > http://www.iana.org/assignments/bgp-well-known-communities/bgp-well-known-communities.xhtml > as we then at least have made the most effort to avoid clashes with > locally significant values. > > At the very least I see operational value in having a well-known > community to tag "customer" prefixes with, this is something I'd use > internally, in public documentation and BCOPs/guides how to set up a BGP > transit network. A "CUSTOMER" community could benefit a group braoder > then the research community.
Proposal specifically is about 16-bit (not 32-bit) values, because it's useful to have the first half be the (16 bit) ASN to which this information applies, ie. <asn>:<color>. This allows route-collectors to also collect this type of information from networks other then their direct peers (modulo bgp selection process, community-stripping). Also if you'd go 32-bit community, because BGP communities are optional transitive, they can easily leak, simple scenario: - 32bit community for tagging customer cone becomes standard - your peer decided to put the 32bit community on all of their customer cone - you receive this feed from your peer - you don't strip the 32bit community either on entrance or exit - result: your competitors customer cone appears tagged as your customer cone to a route collector cheers, Emile _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
