It depends, to clear the cef table At first impact i think it is a tipical loop. You receive 150.1.6.0/24 from bgp internal, exactly 155.1.146.6, from 155.1.13.1 perhaps 13.1 is a RR 146.6 in bgp internal admin 200 is the peering address for the neighbor the route is learned from, thus neighbor 146.6 under bgp if you want reach this prefix probabily you nedd a recursive lookup until a outgoing interface is found, in this case is successfull because is installed in bgp and rib table. also ibgp route cannot adertised to another ibgp peer rather have you got a mutual redistribution also in bgp? thus from bgp in igp ( match community set tag with community list) or mutual redistribution? you verify admin distance to each router you should verify hop by hop You do follow commands sh ip ei in sh ip prot sg bg ipv4 u sh ip ro to each router
On Thu, Feb 2, 2012, at 07:53 PM, Venkee wrote: > > Thanks Marc > > > > On R3, i have captured the following, > > > > Rack1R3(config-router)#do sh ip route 150.1.6.6 > > Routing entry for 150.1.6.0/24 > > Known via "bgp 100", distance 200, metric 0, type internal > > Redistributing via eigrp 100 > > Advertised by eigrp 100 metric 1500 1 255 1 1500 > > Last update from 155.1.146.6 00:18:27 ago > > Routing Descriptor Blocks: > > * 155.1.146.6, from 155.1.13.1, 00:18:27 ago > > Route metric is 0, traffic share count is 1 > > AS Hops 0 > > MPLS label: none > > Rack1R3(config-router)# > > Rack1R3(config-router)#do sh ip cef > > Prefix Next Hop Interface > > 0.0.0.0/0 no route > > 0.0.0.0/8 drop > > 0.0.0.0/32 receive > > 127.0.0.0/8 drop > > 150.1.0.0/16 155.1.37.7 Ethernet0/0 > > 150.1.3.0/24 attached Loopback0 > > 150.1.3.0/32 receive Loopback0 > > 150.1.3.3/32 receive Loopback0 > > 150.1.3.255/32 receive Loopback0 > > 150.1.6.0/24 155.1.37.7 Ethernet0/0 > > > > As per RIB, the next hop shows the 155.1.13.1, but in CEF, 155.1.37.7 as > > next hop, so i think i need to clear the cef table > > > > Please correct if i am wrong > > > > --Venkee > > > > On 2 February 2012 18:19, marc abel <[email protected]> wrote: > > > > > You need to look at the route on the router 155.1.37.7. It is pointing > > > back to R3 for some reason. > > > > > > On Thu, Feb 2, 2012 at 12:54 AM, Venkee <[email protected]> wrote: > > > > > >> Guys, > > >> > > >> While making the setup, i noticed the routing loop, may i know the reason > > >> why ? please help > > >> > > >> Rack1R5#trace 150.1.6.6 > > >> > > >> Type escape sequence to abort. > > >> Tracing the route to 150.1.6.6 > > >> > > >> 1 155.1.0.3 16 msec 20 msec 20 msec > > >> 2 155.1.37.7 20 msec 20 msec 20 msec > > >> 3 155.1.37.3 20 msec 20 msec 20 msec > > >> 4 155.1.37.7 20 msec 24 msec 20 msec > > >> 5 155.1.37.3 20 msec 20 msec 16 msec > > >> 6 155.1.37.7 20 msec 20 msec 20 msec > > >> 7 155.1.37.3 20 msec 20 msec 20 msec > > >> 8 155.1.37.7 20 msec 20 msec 20 msec > > >> 9 155.1.37.3 20 msec 20 msec 20 msec > > >> 10 155.1.37.7 20 msec 20 msec 20 msec > > >> 11 155.1.37.3 16 msec 20 msec 16 msec > > >> 12 155.1.37.7 20 msec 20 msec 20 msec > > >> 13 155.1.37.3 20 msec 20 msec 20 msec > > >> 14 155.1.37.7 20 msec 24 msec 20 msec > > >> 15 155.1.37.3 16 msec 20 msec 20 msec > > >> 16 155.1.37.7 20 msec 20 msec 20 msec > > >> 17 155.1.37.3 20 msec 20 msec 20 msec > > >> 18 155.1.37.7 20 msec 20 msec 20 msec > > >> 19 155.1.37.3 20 msec 16 msec 20 msec > > >> 20 155.1.37.7 20 msec 20 msec 20 msec > > >> > > >> Rack1R3(config-router)#do sh ip route 150.1.6.6 > > >> Routing entry for 150.1.6.0/24 > > >> Known via "bgp 100", distance 200, metric 0, type internal > > >> Redistributing via eigrp 100 > > >> Advertised by eigrp 100 metric 1500 1 255 1 1500 > > >> Last update from 155.1.146.6 00:18:27 ago > > >> Routing Descriptor Blocks: > > >> * 155.1.146.6, from 155.1.13.1, 00:18:27 ago > > >> Route metric is 0, traffic share count is 1 > > >> AS Hops 0 > > >> MPLS label: none > > >> Rack1R3(config-router)# > > >> Rack1R3(config-router)#do sh ip cef > > >> Prefix Next Hop Interface > > >> 0.0.0.0/0 no route > > >> 0.0.0.0/8 drop > > >> 0.0.0.0/32 receive > > >> 127.0.0.0/8 drop > > >> 150.1.0.0/16 155.1.37.7 Ethernet0/0 > > >> 150.1.3.0/24 attached Loopback0 > > >> 150.1.3.0/32 receive Loopback0 > > >> 150.1.3.3/32 receive Loopback0 > > >> 150.1.3.255/32 receive Loopback0 > > >> 150.1.6.0/24 155.1.37.7 Ethernet0/0 > > >> 155.1.0.0/16 155.1.37.7 Ethernet0/0 > > >> 155.1.0.0/24 attached Serial1/0.1 > > >> 155.1.0.0/32 receive Serial1/0.1 > > >> 155.1.0.3/32 receive Serial1/0.1 > > >> 155.1.0.255/32 receive Serial1/0.1 > > >> 155.1.5.0/24 155.1.0.5 Serial1/0.1 > > >> 155.1.7.0/24 155.1.37.7 Ethernet0/0 > > >> 155.1.8.0/24 155.1.0.5 Serial1/0.1 > > >> 155.1.9.0/24 155.1.37.7 Ethernet0/0 > > >> 155.1.10.0/24 155.1.0.5 Serial1/0.1 > > >> 155.1.13.0/24 attached Serial1/2 > > >> 155.1.13.0/32 receive Serial1/2 > > >> > > >> Rack1R3(config-router)#do sh ip cef 150.1.6.0 > > >> 150.1.6.0/24 > > >> nexthop 155.1.37.7 Ethernet0/0 > > >> > > >> do i need to clear the > > >> > > >> Regards, > > >> Venkee > > >> _______________________________________________ > > >> For more information regarding industry leading CCIE Lab training, please > > >> visit www.ipexpert.com > > >> > > >> Are you a CCNP or CCIE and looking for a job? Check out > > >> www.PlatinumPlacement.com > > >> > > >> http://onlinestudylist.com/mailman/listinfo/ccie_rs > > >> > > > > > > > > _______________________________________________ > > For more information regarding industry leading CCIE Lab training, please > > visit www.ipexpert.com > > > > Are you a CCNP or CCIE and looking for a job? Check out > > www.PlatinumPlacement.com > > > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > > > -- > This message is intended for the individual(s) to whom it is addressed > and may contain information that is privileged or confidential. > If you are not the addressee you must not read,use or disclose the > contents of this email. > Whilst all reasonable care has been taken to avoid the transmission of > viruses, the recipient should carry out virus and other checks, > as they consider appropriate. > Myself accepts no responsibility in this regard. > > Ventre Alessandro > > > -- This message is intended for the individual(s) to whom it is addressed and may contain information that is privileged or confidential. If you are not the addressee you must not read,use or disclose the contents of this email. Whilst all reasonable care has been taken to avoid the transmission of viruses, the recipient should carry out virus and other checks, as they consider appropriate. Myself accepts no responsibility in this regard. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
