That does not look right. Can you get 'debug ip os adj' and flap the vlan 50 on either A or C?
Before you do it get: sh ip os int vlan 50 on both Rodney On Thu, Jun 07, 2007 at 12:57:39PM +0300, Hank Nussbacher wrote: > At 05:00 AM 07-06-07 -0400, Rodney Dunn wrote: > >Also depends if you have the priority set and who came up first. > > From the OSPF Design Guide: > http://www.cisco.com/warp/customer/104/1.html > > "DR and BDR election is done via the Hello protocol. Hello packets are > exchanged via IP multicast packets (Appendix B) on each segment. The > router with the highest OSPF priority on a segment will become the DR > for that segment. The same process is repeated for the BDR. In case of a > tie, the router with the highest RID will win. The default for the > interface OSPF priority is one. Remember that the DR and BDR concepts > are per multiaccess segment. Setting the ospf priority on an interface > is done using the ip ospf priority <value> interface command." > > No priority is set. > > So how is it that on router A: > A#sho ip ospf nei > > Neighbor ID Pri State Dead Time Address Interface > 192.168.1.4 1 FULL/DR 00:00:35 10.1.3.2 Vlan50 > 192.168.1.2 1 FULL/DR 00:00:37 10.1.1.2 Vlan20 > > sees 192.168.1.4 as DR and on router C: > C#sho ip ospf nei > > Neighbor ID Pri State Dead Time Address Interface > 192.168.1.1 1 FULL/DR 00:00:37 10.1.3.1 Vlan50 > 192.168.1.3 1 FULL/DR 00:00:38 10.3.3.1 Vlan40 > 192.168.1.2 1 FULL/DR 00:00:30 10.2.2.2 Vlan30 > > on the same VLAN50 it sees 192.168.1.1 as DR? > > See http://www.interall.co.il/vlans.png for simple network schematic. > > There is something I am missing here that I am trying to understand. > > Thanks, > Hank > > > > >What is the uptime of C? > > > >On Thu, Jun 07, 2007 at 11:48:52AM +0300, Hank Nussbacher wrote: > >> What causes a router to become a Designated Router (DR) on a VLAN? I > >> always thought highest router-id, but I have a few test routers and > >here is > >> what I get: > >> > >> C#sho ip ospf nei > >> > >> Neighbor ID Pri State Dead Time Address > >Interface > >> 192.168.1.1 1 FULL/DR 00:00:37 10.1.3.1 Vlan50 > >> 192.168.1.3 1 FULL/DR 00:00:38 10.3.3.1 Vlan40 > >> 192.168.1.2 1 FULL/DR 00:00:30 10.2.2.2 Vlan30 > >> C#sho ip ospf neigh 192.168.1.1 ? > >> C#sho ip ospf neigh 192.168.1.1 deta > >> Neighbor 192.168.1.1, interface address 10.1.3.1 > >> In the area 0 via interface Vlan50 > >> Neighbor priority is 1, State is FULL, 6 state changes > >> DR is 10.1.3.1 BDR is 10.1.3.2 > >> Options is 0x52 > >> LLS Options is 0x1 (LR) > >> Dead timer due in 00:00:34 > >> Neighbor is up for 00:27:35 > >> Index 1/1, retransmission queue length 0, number of retransmission 1 > >> First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) > >> Last retransmission scan length is 1, maximum is 1 > >> Last retransmission scan time is 0 msec, maximum is 0 msec > >> C#sho ip ospf neigh 192.168.1.2 deta > >> Neighbor 192.168.1.2, interface address 10.2.2.2 > >> In the area 0 via interface Vlan30 > >> Neighbor priority is 1, State is FULL, 6 state changes > >> DR is 10.2.2.2 BDR is 10.2.2.1 > >> Options is 0x52 > >> LLS Options is 0x1 (LR) > >> Dead timer due in 00:00:31 > >> Neighbor is up for 00:27:49 > >> Index 3/3, retransmission queue length 0, number of retransmission 0 > >> First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) > >> Last retransmission scan length is 0, maximum is 0 > >> Last retransmission scan time is 0 msec, maximum is 0 msec > >> C#sho ip ospf neigh 192.168.1.3 deta > >> Neighbor 192.168.1.3, interface address 10.3.3.1 > >> In the area 0 via interface Vlan40 > >> Neighbor priority is 1, State is FULL, 6 state changes > >> DR is 10.3.3.1 BDR is 10.3.3.2 > >> Options is 0x52 > >> LLS Options is 0x1 (LR) > >> Dead timer due in 00:00:37 > >> Neighbor is up for 00:28:02 > >> Index 2/2, retransmission queue length 0, number of retransmission 1 > >> First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) > >> Last retransmission scan length is 1, maximum is 1 > >> Last retransmission scan time is 0 msec, maximum is 0 msec > >> > >> IOS 12.3(11)T2 if it makes a difference. > >> > >> All four of them become DR. I have attached a png file that I hope makes > >> it thru the Mailman filter. > >> > >> Thanks, > >> -Hank > > > >> _______________________________________________ > >> cisco-nsp mailing list [email protected] > >> https://puck.nether.net/mailman/listinfo/cisco-nsp > >> archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
