[arin-ppml] 2-byte ASN policy

Michel Py michel at arneill-py.sacramento.ca.us
Sun Apr 3 20:34:09 EDT 2016

> Ron Grant wrote :
> The biggest technical problem with 4-byte ASNs that I'm aware of comes when propagating BGP communities
> - AFAIK even with extended communities, you can't specify two 4-byte ASNs in a single community.

Indeed. I am perverting RT:ASN:Comm (that part does accept and propagate multiple 4-byte ASNs) instead of ROO:ASN:Comm; I wanted to propagate a community that said something about the source of the prefix, not the target. I'm evil.


ip extcommunity-list standard COMM-EX-CBBC permit rt 4200065532:666 rt 4200065532:667

route-map RM-EXABGP permit 10
 set extcommunity rt 4200065532:666 4200065532:667

cisco2821#sh ip bgp x.x.x.x
BGP routing table entry for x.x.x.x/32, version 19852973
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  65532 from (
      Origin IGP, localpref 100, valid, external, best
      Community: 65532:666 65532:667
      Extended Community: RT:4200065532:666 RT:4200065532:667

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