EIGRP a missing route in the topology table

[mohamedayach]

Hello,

From my understanding of what should be in a topology table I think some routes are missing please help me understand.

fo the subnet 192.168.8.0/24 sholdn't they be two routes in the topology table ?

R7#sh ip eigrp topology

IP-EIGRP Topology Table for AS 1

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 192.168.7.0/24, 1 successors, FD is 2816

via Connected, GigabitEthernet0/0

P 192.168.8.0/24, 1 successors, FD is 2170112

via 192.168.78.2 (2170112/2816), Serial0/0/1

P 192.168.78.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/1

P 192.168.79.0/30, 1 successors, FD is 2169856

via Connected, Serial0/1/0

P 192.168.89.0/30, 2 successors, FD is 2681856

via 192.168.78.2 (2681856/2169856), Serial0/0/1

via 192.168.79.2 (2681856/2169856), Serial0/1/0

R8#sh ip eigrp topology

IP-EIGRP Topology Table for AS 1

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 192.168.7.0/24, 1 successors, FD is 2170112

via 192.168.78.1 (2170112/2816), Serial0/0/0

P 192.168.8.0/24, 1 successors, FD is 2816

via Connected, GigabitEthernet0/0

P 192.168.78.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/0

P 192.168.79.0/30, 2 successors, FD is 2681856

via 192.168.78.1 (2681856/2169856), Serial0/0/0

via 192.168.89.2 (2681856/2169856), Serial0/0/1

P 192.168.89.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/1

R9#sh ip eigrp topology

IP-EIGRP Topology Table for AS 1

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 192.168.7.0/24, 1 successors, FD is 2170112

via 192.168.79.1 (2170112/2816), Serial0/0/0

P 192.168.8.0/24, 1 successors, FD is 2170112

via 192.168.89.1 (2170112/2816), Serial0/0/1

P 192.168.78.0/30, 2 successors, FD is 2681856

via 192.168.89.1 (2681856/2169856), Serial0/0/1

via 192.168.79.1 (2681856/2169856), Serial0/0/0

P 192.168.79.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/0

P 192.168.89.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/1

[Jon Marshall]

Can you do a "sh ip eigrp topology all-links" and see what that shows for the subnet.

Jon

[mohamedayach]

Hello,

The same thing!

R7#sh ip eigrp topology all-links

IP-EIGRP Topology Table for AS 1

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 192.168.7.0/24, 1 successors, FD is 2816

via Connected, GigabitEthernet0/0

P 192.168.8.0/24, 1 successors, FD is 2170112

via 192.168.78.2 (2170112/2816), Serial0/0/1

P 192.168.78.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/1

P 192.168.79.0/30, 1 successors, FD is 2169856

via Connected, Serial0/1/0

P 192.168.89.0/30, 2 successors, FD is 2681856

via 192.168.79.2 (2681856/2169856), Serial0/1/0

via 192.168.78.2 (2681856/2169856), Serial0/0/1

[acampbell]

Hi mohamedayach,

When you issue the command "show ip eigrp topology"
you will only see successors & feasable successors

Your second route probably does not qualify as a feasable successor
see this link for an explanation:-
http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/16406-eigrp-toc.html#topologytable

Try issuing the command show ip eigrp topology all-links

Regards
Alex

[mohamedayach]

updated the post thx  in advance! but I thought that the topology table holds all possible routes to all possible subnets ? 

[Jon Marshall]

The topology table does hold all possible routes but when you do a "sh ip eigrp topology" you are not looking at all possible routes, you are only looking at a subset of them.

To see the full topology table you have to use "sh ip eigrp topology all-links".

Jon

[mohamedayach]

Hello

here is the output same result !

R7#sh ip eigrp topology all-links

IP-EIGRP Topology Table for AS 1

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 192.168.7.0/24, 1 successors, FD is 2816

via Connected, GigabitEthernet0/0

P 192.168.8.0/24, 1 successors, FD is 2170112

via 192.168.78.2 (2170112/2816), Serial0/0/1

P 192.168.78.0/30, 1 successors, FD is 2169856

via Connected, Serial0/0/1

P 192.168.79.0/30, 1 successors, FD is 2169856

via Connected, Serial0/1/0

P 192.168.89.0/30, 2 successors, FD is 2681856

via 192.168.79.2 (2681856/2169856), Serial0/1/0

via 192.168.78.2 (2681856/2169856), Serial0/0/1

I gues only FS makes it to the topology table!

[mohamedayach]

Hello back!

Yes I just checked ! u'r right! the other routes ADs do not qualify to make it to the topology tableas FS!

thx again!