Hi Chuck, If you set a community on incoming BGP prefix you could definitely match on it on the same router in your outgoing policy.
Regards, Jeff > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:juniper-nsp- > [EMAIL PROTECTED] On Behalf Of Chuck Anderson > Sent: woensdag 7 februari 2007 7:07 > To: [email protected] > Subject: Re: [j-nsp] BGP session to self over loopback interface? > > > On Feb 6, 2007, at 6:22 PM, Chuck Anderson wrote: > > >Can I create a BGP session from/to a loopback interface on the same > > >router? I want to originate routes into my local BGP table so that I > > >can apply the same export policies locally that I apply on the other > > >routers in my I-BGP mesh. > > On Tue, Feb 06, 2007 at 08:18:57PM -0500, Pete Crocker wrote: > > I'm not sure that makes much sense. Can you give us an example of > > what the goal is? Unlike a cisco, your routes you export to your iBGP > > peers aren't BGP routes on the origination router. They're > > aggregates, statics, ospf routes, connected, etc. It's a different > > way of thinking about it, but I can only assume you're trying to > > apply Cisco redistribution concepts to the Juniper model. An example > > would be great to help you out. > > For example, I would like to originate my BGP advertisements from a > single router, applying communities to control which E-BGP peers will > get the routes, and whether they will have my AS prepended on a > per-neighbor basis: > > /* Originating Router */ > protocols bgp { > group CORE { > type internal; > export [ NEXT-HOP-SELF ORIGINATE ]; > neighbor ... > } > group UPSTREAM1 { > type external; > import [ FROM-UPSTREAM1 REJECT ]; > export [ TO-UPSTREAM1 REJECT ]; > neighbor ... > } > } > policy-options { > policy-statement NEXT-HOP-SELF { > term NEXT-HOP-SELF { > then { > next-hop self; > } > } > } > policy-statement ORIGINATE { > term NET1 { > from { > protocol [ aggregate static ]; > route-filter NET1/MASK1 exact; > } > then { > community add TO-UPSTREAM1; > community add TO-UPSTREAM2-PREPEND1; > accept; > } > } > ... > } > policy-statement TO-UPSTREAM1 { > term NO-PREPEND { > from { > protocol bgp; > community TO-UPSTREAM1; > } > then { > community delete ALL; > accept; > } > } > term ONE-PREPEND { > from { > protocol bgp; > community TO-UPSTREAM1-PREPEND1; > } > then { > community delete ALL; > as-path-prepend ASN; > accept; > } > } > } > } > } > > Then on each of the other routers in the network, I can use the > communities to apply the appropriate export policy actions to each > E-BGP neighbor: > > /* Other Router */ > protocols bgp { > group CORE { > type internal; > export NEXT-HOP-SELF; > neighbor ... > } > group UPSTREAM2 { > type external; > import [ FROM-UPSTREAM2 REJECT ]; > export [ TO-UPSTREAM2 REJECT ]; > neighbor ... > } > > } > policy-options { > policy-statement NEXT-HOP-SELF { > term NEXT-HOP-SELF { > then { > next-hop self; > } > } > } > policy-statement TO-UPSTREAM2 { > term NO-PREPEND { > from { > protocol bgp; > community TO-UPSTREAM2; > } > then { > community delete ALL; > accept; > } > } > term ONE-PREPEND { > from { > protocol bgp; > community TO-UPSTREAM2-PREPEND1; > } > then { > community delete ALL; > as-path-prepend ASN; > accept; > } > } > } > } > > In this example, UPSTREAM2's policy works just fine since it is on > another router that receives the community tagged routes via I-BGP. > However, UPSTREAM1, since it lives on the originating router, cannot > use this method of applying policy as shown above, because the > originating router doesn't have the BGP routes with the communities > applied. Hence I had the idea to get the originating router to behave > like the others by creating a BGP session with itself to get the > routes into inet.0 as type BGP with communities applied. > Unfortunately, I couldn't get the loopback BGP session to work. > > Is there another way to accomplish this? > > Thanks. > _______________________________________________ > 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
