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New Member

Redistribution OSPF-EIGRP

Hi Support

I have a question regarding redistribution in my topology:

On R2 and R3, I have apply redistribution between OSPF 1 and EIGRP 123  and

on R3 I added redistribution between OSPF 1 and EIGRP 356.

First, R4 does not see EIGRP 123 netowrk (174.123.123.0/24) and R1's loopback (150.1.1.1). Thus, could not ping R4 from R1.

kindly explain to me why and what changes i need to apply in R3? 

R4#sh ip route eigr

     174.18.0.0/24 is subnetted, 1 subnets

D EX    174.18.234.0 -----------------------------------------------------------------------------------------> R2,R3,R5 network

           [170/2560002816] via 174.24.24.3, 00:20:01, FastEthernet0/0

     150.2.0.0/32 is subnetted, 1 subnets -------------------------------------------------------------> R2 loopback

D EX    150.2.2.2 [170/2560002816] via 174.24.24.3, 00:20:01, FastEthernet0/0

     150.3.0.0/32 is subnetted, 1 subnets -------------------------------------------------------------> R3 loopback

D EX    150.3.3.3 [170/2560002816] via 174.24.24.3, 00:20:01, FastEthernet0/0

     150.5.0.0/32 is subnetted, 1 subnets -------------------------------------------------------------> R5 loopback

D EX    150.5.5.5 [170/2560002816] via 174.24.24.3, 00:20:01, FastEthernet0/0

Second. Why R1 can see EIGRP 356 network and R4's loopback but only through R2

     174.24.0.0/24 is subnetted, 1 subnets

D EX    174.24.24.0

           [170/2560002816] via 174.123.123.2, 00:19:32, FastEthernet0/0

150.4.0.0/24 is subnetted, 1 subnets

D EX    150.4.4.0

           [170/2560002816] via 174.123.123.2, 00:19:38, FastEthernet0/0

regards

Rommel

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Accepted Solutions
New Member

Redistribution OSPF-EIGRP

HI Rommel,

Can you please provide output of following commands for all routers

sh ip route , sh ip ospf database , sh ip eigrp , sh run.

What I am suspecting is you are not able to see R1 fast ethernet network ( which is connected to R1, R2 and  R3) in R4 routing table.

You are able to see R1 loopback network into R4 routing table after lowering ospf AD as this is getting redistributed by Eigrp 123 into ospf and  from ospf into Eigrp 356.

But the network which is connecting R1, R2 and R3 is learning on R3 is as directly connected and you have not redistributed directly connected network into Eigrp 356.

This network is not getting redistributed by ospf into eigrp 356 because R3 choosing this network  in it's routing table as connected ( because of lower AD 1)  not from ospf.

When you are tring to ping from R1 to R4 loopback , R1 is selecting it's outgoing interface/ip  as source , whch is not present in R4.

If you do extended ping from R1  and choose source as loopback interface ip you will be able to ping R4 loopback ip.

Hope this will help to understand the issue.


 

5 REPLIES
New Member

Redistribution OSPF-EIGRP

New Member

Redistribution OSPF-EIGRP

Hi Rommel,

for the first , on R3 there should be redistribution between Eigrp 123 and Eigrp 356.

Second---R1  can see EIGRP 356 network and R4's loopback but only through R2 because of  you have configured redistribution between ospf and eigrp 356 but not between eigrp 356 and  eigrp123 on R3

Due to this R4 networks( Eigrp 356) are learning on R2 through ospf  and get redistributed in Eigrp 123 ( as you configured redistribution on R2 between ospf and eigrp 123) and learning on R1.

New Member

Re: Redistribution OSPF-EIGRP

Hi Suryakant,

Thank you for your response.

I am trying to understand redistribution from its AD/metric. I dont want to put redistribution between EGRP 123 and EIGRP 356 since EIGRP 123 is already injected in OSPF 1.

R4's should learn the routes of EIGRP 123 from OSPF 1.

when I did a debug on router 3, I noticed the R1 lo 150.1.1.1 is learnt from OSPF 1 AD 110 via R2. Since R3 has also learnt is though R1 Eigrp 123 with AD 90, R3 chooses the lower AD (EIGRP AD 90). Since there is no redistribution between the two EIGRP protocol, R3 will not advertise this route to R4.

when I lower down the OSPF AD to 80 on R3 chosses this and put to its routing table and advetise it to R4. Now i am able to see EIGRP 123 network and able to ping R1 150.1.1.1 from R4 even though its a sub-optimal route.

R4 >> R3 >> R2 >> R1

But from R1 i could not ping R4's loopback 150.4.4.4 though it is on the routing table.

trace route from R1:

R1 >> R2>> stop at R3

On my second question, you are right. thank you for explaining. hope you still can help me in R1.

regards,

Rommel

New Member

Redistribution OSPF-EIGRP

HI Rommel,

Can you please provide output of following commands for all routers

sh ip route , sh ip ospf database , sh ip eigrp , sh run.

What I am suspecting is you are not able to see R1 fast ethernet network ( which is connected to R1, R2 and  R3) in R4 routing table.

You are able to see R1 loopback network into R4 routing table after lowering ospf AD as this is getting redistributed by Eigrp 123 into ospf and  from ospf into Eigrp 356.

But the network which is connecting R1, R2 and R3 is learning on R3 is as directly connected and you have not redistributed directly connected network into Eigrp 356.

This network is not getting redistributed by ospf into eigrp 356 because R3 choosing this network  in it's routing table as connected ( because of lower AD 1)  not from ospf.

When you are tring to ping from R1 to R4 loopback , R1 is selecting it's outgoing interface/ip  as source , whch is not present in R4.

If you do extended ping from R1  and choose source as loopback interface ip you will be able to ping R4 loopback ip.

Hope this will help to understand the issue.


 

New Member

Re: Redistribution OSPF-EIGRP

Hi Suryakant,

Yes, thats what ive observe too. Now i just create an access-list, route-map and redistribute connected with the router-map under ospf .

Cheers!!!!!! Thank you for your assistance and explanation..!

Rommel

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