The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: Aggregate routes Import & export within VRF's on the same PE's
Spice when a VRF say RED import a route from another VRF say green on the same PE's , the VRF red will include the route with next-hop pointing directly to an interface associated with the VRF green . ie: no L3 lookup in VRF green . sure the advantage of doing so is to speed the switching (minimize L3 lookup) . Their is a difference when the route is an aggregate as it does not map to a specific interface and L3 lookup is needed . since the route is an aggregate and could not be maped to a speific interface my guess that such route will not be imported at all in the VRF . Reg the effect of using the loopback : instead of using LB100 and LB200 we will use physical interface's, intf100 and int200 respectively . also we will use intf101 and intf201 . cross connect intf100 and intf101 , cross connect intf200 and intf201 intf100 mintf101 in VRF red , intf200 and intf201 in VRF green . look at the ping : say a ping request with source 10.10.1.1 and destination 10.9.1.1 recieved at VRF red ,it will be switched to intf200 . looped to intf201 and as usual a L3 lookup in VRF green will direct the packet to intf3 . The ping reply with source 10.9.1.1 and destination 10.10.1.1 is received at VRF green and switched to intf100. looped to intf101 and as usual a L3 lookup in VRF Red will direct the packet to intf1 and connectivity between the 2 VRF is achieved . My guess : The LB100 could be a replacement for intf100 and intf101 and the cross connect between them. LB200 is the replacement for intf200 and intf201 and the cross connect between them. When LB100 recieved a packet with destination is not the LB100 itself ,my guess that the action will be to do L3 lookup in the routing table (which is VRF RED routing table ,as LB100 is associated with VRF RED) . similarly for LB200 . Hopefully i clarified the case and not making it more confusing . Brgds >From: Spice Sylvia <falsesylvia@yahoo.co.uk> >To: "M. ELK" <elkou141061@hotmail.com> >Subject: Re: [MPLS-OPS]: Aggregate routes Import & export within VRF's on >the same PE's >Date: Tue, 27 Jan 2004 15:14:57 +0000 (GMT) > >Hi, > >Please see inline.. > >"M. ELK" <elkou141061@hotmail.com> wrote: > > >Say at PE1 we have the following config : > >ip vrf red >rd 1:1 >import 1:10 >export 1:20 > >ip route vrf red 10.10.1.0/24 intf1 >ip route vrf red 10.10.2.0/24 intf2 > >address-family ipv4 vrf red >redistribute static >aggregate-address 10.10.0.0 255.255.0.0 >exit-address-family > >ip vrf green >rd 1:2 >import 1:20 >export 1:10 > >ip route vrf green 10.9.1.0/24 intf3 >ip route vrf green 10.9.2.0/24 intf4 > >address-family ipv4 vrf green >redistribute static >aggregate-address 10.9.0.0 255.255.0.0 >exit-address-family > > >1- If we assume that any implementation should not differentiate between >VRF's on different >PE's and VRF's on the same PE's so : >VRF red will have a route 10.9/16 ,and VRF green will have a route >10.10/16 . >is any implem able to do that ? >if yes : say for 10.9/16 in VRF red , what will be the Next_hop interface >??? . > > > > > >-------> the case below is the same as this case..I am not too sure why >Cisco does it this way if theyb do so...but by pure logic... > >you are anyways looking at the case of an L3 Lookup. > >So the nexthop (though its an aggregate) can be the specific route to the >interface as seen in each VRF. How does adding a loopback and doing an L3 >lookup make things different? > >You could have done the L3 Lookup within the VRF itself... > > > >------------------------------------------ > >2- Specific to cisco implementation . >guess the above as configured is not workable ,ie: 10.9/16 will not show >in VRF red >neither 10.10/16 in VRF green , is it correct ? >if yes : assume we added the following >loopback 100 associated with VRF red . >loopback 200 associated with VRF green . >ip route vrf red 10.10./16 LB100 >ip route vrf green 10.9/16 LB200 > >is 10.9/16 will appear in VRF red with next_hop = LB200 ,similiarly >10.10/16 will appear in VRF green with next_hop = LB100 . > >. > >is the above workable ??? >note : i have no access to a test bed to confirm the above . > >Brgds > >_________________________________________________________________ >MSN 8 with e-mail virus protection service: 2 months FREE* >http://join.msn.com/?page=features/virus > >------- >The MPLS-OPS Mailing List >Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml >Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > > >--------------------------------- >BT Yahoo! Broadband - Free modem offer, sign up online today and save £80 _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963 ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml |
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