Solved: Re: no EIGRP neighship is being formed. - Page 2

prabinchand · ‎01-09-2022

Hello EXPERTS,

I have configured EIGRP 100 on HEAD-OFFICE and BRANCH-1 but no neighborship is formed. OR i haven't understood the routing properly, if so, please make me clear. I will be very thankful to you guys!!.

Topology is attached below.

no any config shoud be applied on ISP side.

CONFIGURATION

ISP-INTERNET:

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname Router

!

!

!

!

!

!

!

!

ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2911/K9 sn FTX15245A44-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface GigabitEthernet0/0

no ip address

duplex auto

speed auto

shutdown

!

interface GigabitEthernet0/1

no ip address

duplex auto

speed auto

shutdown

!

interface GigabitEthernet0/2

no ip address

duplex auto

speed auto

shutdown

!

interface Serial0/3/0

ip address 1.1.1.2 255.255.255.252

clock rate 2000000

!

interface Serial0/3/1

ip address 2.2.2.2 255.255.255.252

clock rate 2000000

!

interface Vlan1

no ip address

shutdown

!

ip classless

ip route 0.0.0.0 0.0.0.0 2.2.2.1

ip route 0.0.0.0 0.0.0.0 1.1.1.1

!

ip flow-export version 9

!

!

!

no cdp run

!

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

HEAD-OFFICE:

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname HEAD-OFFICE

!

!

!

!

!

!

!

!

no ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2911/K9 sn FTX1524JH3H-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface GigabitEthernet0/0

ip address 192.168.10.1 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/1

ip address 192.168.20.1 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/2

ip address 192.168.50.1 255.255.255.0

duplex auto

speed auto

!

interface Serial0/3/0

ip address 1.1.1.1 255.255.255.252

!

interface Serial0/3/1

no ip address

clock rate 2000000

shutdown

!

interface Vlan1

no ip address

shutdown

!

router eigrp 100

network 192.168.10.0

network 192.168.20.0

network 1.1.1.0 0.0.0.3

network 192.168.50.0




!

ip classless

!

ip flow-export version 9

!

!

!

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

BRANCH-1:

Current configuration : 1226 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname BRANCH-1

!

!

!

enable secret 5 $1$mERr$aI/DxI917YEQARn3zkBDJ0

!

!

!

!

!

aaa new-model

!

aaa authentication login default group radius local

!

!

!

aaa accounting exec default start-stop group radius

!

!

!

!

ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2911/K9 sn FTX1524NG67-

!

!

!

!

!

!

!

!

!

ip ssh version 2

ip domain-name cisco.com

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface GigabitEthernet0/0

ip address 192.168.30.1 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/1

no ip address

duplex auto

speed auto

shutdown

!

interface GigabitEthernet0/2

no ip address

duplex auto

speed auto

shutdown

!

interface Serial0/3/0

no ip address

clock rate 2000000

shutdown

!

interface Serial0/3/1

ip address 2.2.2.1 255.255.255.252

!

interface Vlan1

no ip address

shutdown

!

router eigrp 100

network 192.168.30.0

network 2.2.2.0 0.0.0.3




!

ip classless

!

ip flow-export version 9

!

!

!

!

radius-server host 192.168.20.2 auth-port 1645 key i@mradius

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

line vty 5 10

login authentication default

!

!

!

end

Richard Burts · ‎01-10-2022

The original post asks " OR i haven't understood the routing properly," Pretty clearly the understanding of routing is not correct. A fundamental aspect of running EIGRP is that a neighbor relationship is formed only when the routers involved are connected on a common subnet. Head-Office is running "EIGRP on Serial0/3/0" and Branch-1 is running "EIGRP on Serial0/3/1". But these interfaces are not on a common subnet and so no neighbor relationship is formed.

There are several ways that the original poster can get this to work.

1) run EIGRP on both serial interfaces of ISP router. But a requirement in the original post is that no changes are to be made on ISP router. So this would not work.

2) configure a simple GRE tunnel between Head-Office and Branch-1 and run EIGRP on the tunnel interface (removing the network statements for the serial interfaces). This would be the most simple solution.

3) configure an encrypted tunnel between Head-Office and Branch-1 and run EIGRP over the encrypted tunnel. This might be DMVPN, or VTI, or ipsec over GRE.

HTH

Rick

prabinchand · ‎01-10-2022

i tired your suggestion number.2 but it didn't worked.

My quesiton is, how can branch communicate with Head office when it dont know the route for head office.

Using 2nd suggestion i did the same as u said but yet no neighborship is formed and condition is i cannot use any static route on HEADOFFICE AND BRANCH.

now what will be the way?

paul driver · ‎01-10-2022

Hello

@prabinchand wrote:

i tired your suggestion number.2 but it didn't worked.

My quesiton is, how can branch communicate with Head office when it dont know the route for head office.

.Well it wont be able to connect - you need some sort of transit path between the head/branch offices, be it via the internet or direct connection, at least some sort of connectivity.

example
If the head off and branch offices are internet facing then the internet is the transit path as such you would then secure that connection with say an "ipsec/gre" tunnel and run eigrp over that tunnel.

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

prabinchand · ‎01-10-2022

ISP has provided different network for HEAD-OFFICE and BRANCH so how can i do communicate those between without using statice route. Default route can only be applied on ISP router & HEAD-OFFICE and BRANCH should use EIGRP.

What can be the solution for this ?

paul driver · ‎01-10-2022

Hello

I assume your branch office has a isp circuit? (internet/mpls etc..) And your head off has a internet facing presence?

Can you confirm the transit connectivity?

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

prabinchand · ‎01-10-2022

i dont know about those transit sir, I am doing this lab on my own. I got curious, how can branch and head office can commmunicate without using any static ip.

Georg Pauwen · ‎01-10-2022

Hello,

--> I am doing this lab on my own

Are you following any instructions at all, or did you come up with the topology (and subsequent question) by yourself ? We are under the assumption that you are following a scripted lab. If that is not the case, the answer is simply: no, it won't work. As @paul driver mentioned, you need a common subnet between EIGRP neighbors.

paul driver · ‎01-10-2022

Hello

@prabinchand wrote:

i dont know about those transit sir, I am doing this lab on my own. I got curious, how can branch and head office can commmunicate without using any static ip.

okay pick an ip range that the Hq /branch rtts can communicate on.

The below example should provide eigrp adjacency between HQ and Branch office.

HQ

int x/x
description link to branch
ip address 10.1.12.1 255.255.255.252

router eigrp 1
no auto
network 10.1.12.1 0.0.0.0

Branch

int x/x
description link to HO
ip address 10.1.12.2 255.255.255.252

router eigrp 1
no auto
network 10.1.12.2 0.0.0.0

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

MHM Cisco World · ‎01-10-2022

...

Richard Burts · ‎01-10-2022

The original poster has created a set of mutually contradictory requirements. The Head Office knows 3 connected LAN subnets and a potential transit network over the serial interface. But it has no other routing knowledge. The Branch knows 1 connected LAN subnet and a potential transit network over the serial interface. So both the Head Office and the Branch know locally connected subnets but have no routing logic for anything remote. And the other condition is:

Condition is no any static route shoud be used on BRANCH and HEAD-OFFICE.

Given this requirement there is no way for this project to work.

For this project to work either the ISP router needs additional routing information, in particular if the ISP router would run EIGRP with the other 2 routers it would be successful. Or if the Head Office and Branch had some default route it would be successful. Or if the Head Office and the Branch had a route for the transit network of the other side it would work. But with the current restrictions I do not see any way that it could work.

HTH

Rick