It seems to be dependent on the type of summary. For example a summary which is installed as null0 route should cause an aggregate label to exist. For the rest I also only saw these kinds of labels within MPLS VPNs, sometimes not even caused by summaries :-) Try using BGP for example, doing a send-label and an aggregate-address. Try if you see an aggregate label then.
-- Regards, Rick Mur CCIE2 #21946 (R&S / Service Provider) Juniper JNCIA-ER & JNCIA-EX MCSA:Messaging, MCSE Sr. Support Engineer – IPexpert, Inc. URL: http://www.IPexpert.com On Tue, Jun 30, 2009 at 5:37 PM, Bryan Bartik <[email protected]> wrote: > Hello, > > I have read that when an "Aggregate" label shows up in the LFIB, the > LSR must remove the label and do an IP lookup to determine how to > forward the packet. The only scenario for which I can seem to create > this is in an MPLS VPN. I have also read that when you perform route > summarization, you may see an "Aggregate" label, however I cannot > produce these results. (From MPLS Fundamentals, p131 "Aggregate labels > can be the result of aggregation or summarization of IP prefixes in > the network.") > > Here is the scenario I am testing: > > R3---R1---R2---R4---R5 > > R2 is the ABR performing summarization for two loopbacks on R5 > (150.100.0.5/32, 150.100.1.5/32). Summary is 150.100.0.0/16. > > Notice that R2 still has both labels, there is no "Aggregate"...and it > advertises an implicit null to R1. > > R2#sho mpls forwarding-table > Local Outgoing Prefix Bytes tag Outgoing Next Hop > tag tag or VC or Tunnel Id switched interface > 16 Pop tag 10.1.1.1/32 0 Se1/1 point2point > 17 Pop tag 192.168.13.0/24 0 Se1/1 point2point > 18 18 10.1.1.3/32 0 Se1/1 point2point > 20 Pop tag 10.1.1.4/32 0 Se1/0 point2point > 21 Pop tag 150.100.45.0/24 0 Se1/0 point2point > 22 21 150.100.1.5/32 0 Se1/0 point2point > 23 22 150.100.0.5/32 0 Se1/0 point2point > 25 23 10.1.1.5/32 0 Se1/0 point2point > > R1#sho mpls forwarding-table > Local Outgoing Prefix Bytes tag Outgoing Next Hop > tag tag or VC or Tunnel Id switched interface > 16 Pop tag 192.168.24.0/24 0 Se1/0 point2point > 17 Pop tag 10.1.1.2/32 0 Se1/0 point2point > 18 Pop tag 10.1.1.3/32 0 Se1/1 point2point > 19 Pop tag 150.100.0.0/16 0 Se1/0 point2point > 20 20 10.1.1.4/32 0 Se1/0 point2point > 25 25 10.1.1.5/32 0 Se1/0 point2point > > Now this seems all fine to me, R2 must do an IP lookup when it > receives the unlabeled packets, and then it labels them before > forwarding them. > > Why doesn't the output on R2 show "Aggregate"? > Am I misunderstanding the use of "Aggregate"? > > Thanks, > > -- > Bryan Bartik > CCIE #23707 (R&S), CCNP > Sr. Support Engineer - IPexpert, Inc. > URL: http://www.IPexpert.com > > _____________________________________________________________________ > Subscription information: http://www.groupstudy.com/list/comserv.html >
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