EIGRP Stub Mindmaps and Configurations

In this post, I will be sharing various types of EIGRP Stub routers.

Default EIGRP Stub CONFIGURATIONS

EIGRP Configurations of MANILA Router:

R1#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#hostname MANILA
MANILA(config)#int s2/0
MANILA(config-if)#ip address 192.168.12.1 255.255.255.0
MANILA(config-if)#no shut
MANILA(config)#int lo1
MANILA(config-if)#ip add 100.100.100.1 255.255.255.0
MANILA(config-if)#exit

MANILA(config)#router eigrp 12
MANILA(config-router)#network 192.168.12.0
MANILA(config-router)#network 100.100.100.0 0.0.0.255
MANILA(config-router)#no auto-summary

EIGRP Configurations of MELBOURNE Router:

R2#config t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#hostname MELBOURNE
MELBOURNE(config)#int s2/0
MELBOURNE(config-if)#ip address 192.168.12.2 255.255.255.0
MELBOURNE(config-if)#no shut
MELBOURNE(config-if)#exit
MELBOURNE(config)#int lo1
MELBOURNE(config-if)#ip add 200.200.200.1 255.255.255.0

MELBOURNE(config)#router eigrp 12
MELBOURNE(config-router)#network 192.168.12.0
MELBOURNE(config-router)#network 200.200.200.0 0.0.0.255
MELBOURNE(config-router)#no auto-summary
MELBOURNE(config-router)#exit
MELBOURNE(config-router)#^Z
MELBOURNE#

VERIFICATION:

As observed, both routers are receiving the Loopback address being advertise on each locations.

MANILA#sh ip route eigrp
Codes: L – local, 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, H – NHRP, l – LISP
       + – replicated route, % – next hop override

Gateway of last resort is not set

D 200.200.200.0/24 [90/2297856] via 192.168.12.2, 00:07:16, Serial2/0

MELBOURNE#sh ip route eigrp
Codes: L – local, 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, H – NHRP, l – LISP
       + – replicated route, % – next hop override

Gateway of last resort is not set

100.0.0.0/24 is subnetted, 1 subnets
D 100.100.100.0 [90/2297856] via 192.168.12.1, 00:00:36, Serial2/0

Let me shutdown the Loopback interface on MANILA router and enabled “debug eigrp packets query”on both MANILA and MELBOURNE Router.

MANILA#debug eigrp packets query
(QUERY)
EIGRP Packet debugging is on
MANILA#config t
Enter configuration commands, one per line. End with CNTL/Z.
MANILA(config)#int lo1
MANILA(config-if)#shut
MANILA(config-if)#

As observed below, I can see that MANILA router is sending a query packet to MELBOURNE router.

MANILA#
*Jul 14 23:28:45.667: EIGRP: Enqueueing QUERY on Se2/0 – paklen 0 tid 0 iidbQ un/rely 0/1 serno 7-7
*Jul 14 23:28:45.671: EIGRP: Enqueueing QUERY on Se2/0 – paklen 0 nbr 192.168.12.2 tid 0 iidbQ un/rely 0/0 pee
*Jul 14 23:28:45.687: EIGRP: Sending QUERY on Se2/0 – paklen 44 nbr 192.168.12.2 tid 0
*Jul 14 23:28:45.691: AS 12, Flags 0x0:(NULL), Seq 7/6 interfaceQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 se
Capturing the console logs from the MELBOURNE router, it shows that it has received a query from MANILA router.

MELBOURNE#debug eigrp packets query
(QUERY)
EIGRP Packet debugging is on
MELBOURNE#
*Jul 14 23:26:31.691: EIGRP: Received QUERY on Se2/0 – paklen 44 nbr 192.168.12.1
*Jul 14 23:26:31.691: AS 12, Flags 0x0:(NULL), Seq 5/4 interfaceQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

Now, I will be enabling the DEFAULT STUB which is CONNECTED and SUMMARY on MELBOURNE routers.

MELBOURNE#config t
Enter configuration commands, one per line. End with CNTL/Z.
MELBOURNE(config)#router eigrp 12
MELBOURNE(config-router)#eigrp stub

*Jul 14 23:53:27.607: %DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 192.168.12.1 (Serial2/0) is down: peer info changed
*Jul 14 23:53:28.155: %SYS-5-CONFIG_I: Configured from console by console
MELBOURNE#
*Jul 14 23:53:29.547: %DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 192.168.12.1 (Serial2/0) is up: new adjacency
MELBOURNE#

As noticed the moment that I have enabled eigrp stub, the adjacency were reset.

As expected, the EIGRP configurations would show the default stub.

MELBOURNE#sh run | section eigrp
router eigrp 12
network 192.168.12.0
network 200.200.200.0
eigrp stub connected summary

Now, I will be shutting down the MELBOURNE Loopback Interface and check the results of the “debug eigrp packet query”. Let’s see what happens.

MELBOURNE#config t
Enter configuration commands, one per line. End with CNTL/Z.
MELBOURNE(config)#int lo 1
MELBOURNE(config-if)#shutAs observed below, the MELBOURNE router is sending q QUERY packet to MANILA router.

MELBOURNE(config-if)#
*Jul 16 10:13:00.635: EIGRP: Enqueueing QUERY on Se2/0 – paklen 0 tid 0 iidbQ un/rely 0/1 serno 9-9
*Jul 16 10:13:00.639: EIGRP: Enqueueing QUERY on Se2/0 – paklen 0 nbr 192.168.12.1 tid 0 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 9-9
*Jul 16 10:13:00.655: EIGRP: Sending QUERY on Se2/0 – paklen 44 nbr 192.168.12.1 tid 0
*Jul 16 10:13:00.659: AS 12, Flags 0x0:(NULL), Seq 7/6 interfaceQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 9-9
While MANILA is receiving the QUERY Packet.

MANILA#
*Jul 16 10:12:33.299: EIGRP: Received QUERY on Se2/0 – paklen 44 nbr 192.168.12.2
*Jul 16 10:12:33.299: AS 12, Flags 0x0:(NULL), Seq 7/6 interfaceQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

NETWORK LESSON