Forwarding address must be reachable via OSPF in order to be used. If it's unreachable, or reachable via external route, LSA will be ignored when calculating the RIB.
-- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Sat, Nov 20, 2010 at 05:48, Taqdir Singh <[email protected]> wrote: > hi all, > > I was reading some articiles on forwarding address in OSPF but have small > doubt > > Please see attached diagram. > > R3 has static route to 1.1.1.1 and redistributing it into OSPF area 0 > between R2 and R3, > > > so, R2 gets route 1.1.1.1 with forwarding address of 0.0.0.0. > > in order to make next hop as 10.0.123.1 on R2 for route 1.1.1.1, we need to > put one interface into OSPF on R3. > > But adjacency is not required as per articles > > So i get LSA on R2 for 1.1.1.1 and forwarding address of 10.0.123.1, but > this doesnt get intsalled into RIB until unless I run OSPF between R2 and R3 > over subnet 10.0.123.0. > > Please see my configs...I am doing something wrong ? or adjaceny between R2 > and R3 is required over 10.0.123.0 > > As you can see below, its in Database but not in RIB > > > R2#sh run | s ospf > router ospf 1 > log-adjacency-changes > network 10.0.23.0 0.0.0.255 area 0 > R2#sh ip os da ex 1.1.1.1 > OSPF Router with ID (10.0.123.2) (Process ID 1) > Type-5 AS External Link States > LS age: 393 > Options: (No TOS-capability, DC) > LS Type: AS External Link > Link State ID: 1.1.1.1 (External Network Number ) > Advertising Router: 10.0.123.3 > LS Seq Number: 80000002 > Checksum: 0xACDF > Length: 36 > Network Mask: /32 > Metric Type: 2 (Larger than any link state path) > TOS: 0 > Metric: 20 > Forward Address: 10.0.123.1 > External Route Tag: 0 > R2#sh ip ro > R2#sh ip route > Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP > D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area > N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 > E1 - OSPF external type 1, E2 - OSPF external type 2 > i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 > ia - IS-IS inter area, * - candidate default, U - per-user static > route > o - ODR, P - periodic downloaded static route > Gateway of last resort is not set > 10.0.0.0/24 is subnetted, 2 subnets > C 10.0.23.0 is directly connected, FastEthernet0/5 > C 10.0.123.0 is directly connected, FastEthernet0/2 > R2# > > > R2#sh run | s ospf > router ospf 1 > log-adjacency-changes > network 10.0.23.0 0.0.0.255 area 0 > R2# > > R3#sh run | s ospf > router ospf 1 > log-adjacency-changes > redistribute static subnets > network 10.0.23.0 0.0.0.255 area 0 > network 10.0.123.0 0.0.0.255 area 0 > R3# > > > > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
