EIGRP not forming adjacency

[juanmacipag2020]

Hi All,

I have two different subnets
R1: 10.254.1.240 /29
R2: 10.254.1.248 /29

R1: g1/1: IP add 10.254.1.241 255.255.255.248
is directly connected to an L3
L3: g1/2 ip add 10.254.1.242 255.255.255.248

and the other side is:

R2: g1/1: ip add 10.254.1.249 255.255.255.248
is directly connected to an L3
L3: g1/2 ip add 10.254.1.250 255.255.255.248

My EIGRP configs are:
for both L2 & L3:
router eigrp 1000
no auto-summ
network 10.254.1.0 0.0.0.7

EIGRP does not form an adjacency.

Can you tell me what am I missing?

Thanks

[Georg Pauwen]

Hello,

if you announce 'network 10.254.1.0 0.0.0.7' that only covers hosts 10.254.1.1 - 10.254.1.6. Change your network statement toL

network 10.254.1.0 0.0.0.255

EDIT: Make sure you announce the same network 10.254.1.0 0.0.0.255 on both routers as well...

[juanmacipag2020]

Thanks Greg!

If I use network 10.254.1.0 0.0.0.255 or your other suggestions

Ill be advertizing all subnets. 

Since I only need to advertise these range of subnets. My EIGRP routing table is more specific

network 10.254.1.240 0.0.0.7

network 10.254.1.248 0.0.0.7

[Richard Burts]

There are several things to address about this issue.

First is that based on what you have given us so far we do not see any connection between these routers. If they are connected please explain to us what this connection is, and how it relates to your EIGRP configuration.

Second thing to address is that your EIGRP network statement of 

network 10.254.1.0 0.0.0.7

does not match the subnets used on your routers. (that network statement would match addresses from 10.254.1.0 through 10.254.1.7). If you use the command show ip eigrp interface I believe that you will find that there are no active EIGRP interfaces.

[juanmacipag2020]

Ok thanks. heres the topolopgy

There is no direct connection between R1 & R2
However, they communicate through L3 switches

R1: 10.254.1.240 /29
R2: 10.254.1.248 /29

R1 R2
| |
| |
| |
| |
| |
| |

SW1 -------------------SW2

SW1 & SW2 VLANs
VLAN1
10.1.21.0/24
VLAN2
10.1.22.0/26
VLAN3
10.1.41.0/27
VLAN4
10.1.22.0/28

[Georg Pauwen]

Hello,

actually, if you want to be really accurate, just announce the host addresses of the interfaces:

R1

router eigrp 1000
network 10.254.1.241 0.0.0.0

L3

router eigrp 1000
network 10.254.1.242 0.0.0.0

R2

router eigrp 1000
network 10.254.1.249 0.0.0.0

L3

router eigrp 1000
network 10.254.1.250 0.0.0.0

[juanmacipag2020]

but which one redudes the amount of the routing tables? 

network 10.254.1.0 0.0.0.255

or

R1

router eigrp 1000
network 10.254.1.241 0.0.0.0

L3

router eigrp 1000
network 10.254.1.242 0.0.0.0

R2

router eigrp 1000
network 10.254.1.249 0.0.0.0

L3

router eigrp 1000
network 10.254.1.250 0.0.0.0

[Georg Pauwen · Accepted solution]

Hello,

what do you mean by 'reduces the amount of the routing table' ?

Use the second option. The network statement is used to tell the EIGRP process which interfaces participate in EIGRP.

Use these entries:

R1

router eigrp 1000
network 10.254.1.241 0.0.0.0

L3

router eigrp 1000
network 10.254.1.242 0.0.0.0

R2

router eigrp 1000
network 10.254.1.249 0.0.0.0

L3

router eigrp 1000
network 10.254.1.250 0.0.0.0

[juanmacipag2020]

Thank you Georg Pauwen 

Last question if you are to choose w/c is the solution will you choose and why?

Solution # 1 

router eigrp 1000

R1: network 10.254.1.241 0.0.0.0
L3: network 10.254.1.242 0.0.0.0
R2: network 10.254.1.249 0.0.0.0
L3: network 10.254.1.250 0.0.0.0

Solution # 2

router eigrp 1000

For R1 & L3: network 10.254.1.240 0.0.0.7
For R2 & L3: network 10.254.1.248 0.0.0.7

Solution # 3

router eigrp 1000

network 10.254.1.0 0.0.0.255

[Jon Marshall]

The network statement just tells EIGRP which interfaces to start up on. 

So if you have other interfaces that are part of the 10.254.1.0/24 subnet then that would create more route entries in the IP routing table. 

Jon

[juanmacipag2020]

Understood thank you  Jon Marshall +++