23456 was reserved as a compatibility ASN to sort of make things compatible with 2-byte implementations. There is a lot of information on the interweb so I wont go into detail here.
Phil From: Markus Sent: Wednesday, May 21, 2014 5:33 PM To: juniper-nsp@puck.nether.net List PS: On a second thought, of course as-path-prepend will make the session get dropped by the remote router, because my AS is not first in the path anymore. My mistake, so please ignore that. I checked some more looking glasses in the meantime and I can see my-upstream my-asn 222222 at some of them. Only one looking glass showed me my-upsteam my-asn 23456, so I'm thinking maybe everything is fine and only this particular LG cannot display 4-byte ASN and uses 23456 instead? Sorry for the noise in that case. :) Am 21.05.2014 23:20, schrieb Markus: > Hi list! > > I'm trying to prepend a customers 4-byte ASN to their prefixes. JunOS > 12.3R2.5 on M7i. This is my config, simplified: > > [routing-options static] > route a.a.a.a/22 { > next-hop b.b.b.b; > readvertise; > } > > [policy-options] > policy-statement UPSTREAM-OUT { > term 1 { > from { > route-filter a.a.a.a/22 exact; > } > then { > as-path-expand 222222; > } > } > > UPSTREAM-OUT is applied as export to my upstream's BGP peer. So far so > good: > > admin@router# run show route advertising-protocol bgp my-upstream-ip > > Prefix Nexthop MED Lclpref AS path > * a.a.a.a/22 Self 10 222222 I > > But when I check a public looking glass I can see that 222222 becomes > 23456: > > 3257 1299 my-upstream my-asn 23456 > > I changed "as-path-expand" to "as-path-prepend" and this resulted in the > BGP session to drop and I can see this in my log: > > router rpd[1567]: bgp_read_v4_message:10289: NOTIFICATION received from > my-upstream-ip (External AS my-upstream): code 3 (Update Message Error) > subcode 11 (AS path attribute problem), Data: 40 02 0a 02 02 00 > > Does this maybe mean that my upstream routers software does not yet > support 4-byte ASNs? > > I'm also doing the same to various peers and there it works fine. I can > see the path "my-asn 222222" in my peers looking glasses. > > Thanks! > Markus > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp