Stub routing with leak-map

In this scenario we should achieve the stub routing as well as the we should leak some route.

To get this work we have a different kind of stub routing. Because stub routing doesn't support the leak-map.

To achieve the leak-map and stub feature we can go from summarization.

Summarization is also  eliminate the query domain.

Ok now lets take the example on R2 should be leak some BB1 route and R2 should act as a stub.

In this case summarize the router on R2.

R1#sh ip route

     111.0.0.0/24 is subnetted, 5 subnets

D       111.1.4.0 [90/2323456] via 155.1.123.2, 00:00:08, Serial0/0.123

D       111.1.5.0 [90/2323456] via 155.1.123.2, 00:00:08, Serial0/0.123

D       111.1.2.0 [90/2323456] via 155.1.123.2, 00:00:08, Serial0/0.123

D       111.1.3.0 [90/2323456] via 155.1.123.2, 00:00:08, Serial0/0.123

D       111.1.1.0 [90/2323456] via 155.1.123.2, 00:04:09, Serial0/0.123

In R1 we are getting route 111.0.0.0/24 in 5 subnets. Now lets make R2 as stub and leak the 111.1.1.0/24 route in R1.

R2#sh run

interface Serial0/0

 ip address 155.1.123.2 255.255.255.0

 encapsulation frame-relay

 ip summary-address eigrp 100 111.1.0.0 255.255.248.0 5 leak-map BB1

 serial restart-delay 0

end

R2#sh run

access-list 1 permit 111.1.1.0 0.0.0.255

!

route-map BB1 permit 10

 match ip address 1

R1#sh ip route

     111.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

D       111.1.0.0/21 [90/2323456] via 155.1.123.2, 00:00:07, Serial0/0.123

D       111.1.1.0/24 [90/2323456] via 155.1.123.2, 00:06:39, Serial0/0.123

Summarization and leak-map working fine but now lets check for stub routing. To verify this lets shutdown the loopback interface 4. And run debug query in R5 and R1.

R1#

Mar  1 00:43:09.055: EIGRP: Received QUERY on Serial0/0.123 nbr 155.1.123.2

Mar  1 00:43:09.059:   AS 100, Flags 0x0, Seq 74/124 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

Mar  1 00:43:09.075: EIGRP: Enqueueing REPLY on Serial0/0.123 nbr 155.1.123.2 iidbQ un/rely 0/1 peerQ un/rely 0/0 serno 124-124

Mar  1 00:43:09.087: EIGRP: Sending REPLY on Serial0/0.123 nbr 155.1.123.2

Mar  1 00:43:09.091:   AS 100, Flags 0x0, Seq 125/74 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 124-124

R1 gets the query and immediately forwards the reply to R2 saying we don’t have the reachability to the lost network.

On R5 we didn’t get ant query packet from R1.