strange behaviour of a cisco 2600

cpaadministrator · ‎11-15-2005

Hello,

I got a problem with a Cisco 2600. This router has 2 WAN interfaces. 1 serial for leased line connection and 1 BRi for ISDN backup.

When the main link is down the bri automatically connects to another router a cisco 3640.

when the isdn link is established no ping from the romte side and the other way round is possible. when the main link (serial) is connected the ping is possible and works fine.

when the isdn is connected I can connect me to the isdn interface of the cisco 2600. so the isdn itself works.

when i make ping from the side of the cisco 3640 it tells me that the remote nezwork is not reachable.

I do not think that the routing is wrong because the whole time it works and nothing changed.

the routing is like the following:

both the cisco 3640 and 2600 has a loopback interface which the routing point to. so nothing has to be changed when the main link is down.

I can´t imagine why this does not work.

I will post the config to show it more clearly.

Kai

cpaadministrator · ‎11-15-2005

Here is the config of the cisco 2600:

version 12.3

no service pad

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname cisco2600

!

boot-start-marker

boot-end-marker

!

enable password 7 050A160C381E45

!

username cisco3640 password 7 12383534

no aaa new-model

ip subnet-zero

!

isdn switch-type basic-net3

!

interface Loopback0

ip address 192.168.103.20 255.255.255.255

!

interface FastEthernet0/0

ip address 192.168.123.99 255.255.255.0

duplex auto

speed auto

!

interface Serial0/0

description 2MBit connection

ip address 192.168.110.2 255.255.255.0

encapsulation ppp

backup delay 5 60

backup interface BRI0/0

no ip route-cache

no ip mroute-cache

!

interface BRI0/0

ip address 192.168.109.27 255.255.255.0

encapsulation ppp

no ip mroute-cache

dialer map ip 192.168.109.1 name cisco3640 broadcast xxxxxxx

dialer load-threshold 1 either

dialer-group 1

isdn switch-type basic-net3

compress stac

ppp authentication chap

!

router eigrp 1

network 192.168.103.0

network 192.168.109.0

network 192.168.110.0

auto-summary

!

no ip http server

ip classless

ip route 192.168.9.200 255.255.255.224 192.168.103.1

ip route 192.168.100.42 255.255.255.255 192.168.103.1

ip route 192.168.103.1 255.255.255.255 192.168.109.1 200

!

dialer-list 1 protocol ip permit

!

line con 0

password 7 106F393A

line aux 0

line vty 0 4

password 7 11282926

login

!

end

spremkumar · ‎11-15-2005

Hi

Do revert back whats is 192.168.103.1 is it your remote end loopback ip ?

Also 192.168.9.200 as well as 100.42 which you have routed towards 103.1

have u checked whether you are getting valid route there in 3600 for your 2600 locations network or loopback ip once you are on ISDN ??

you can always check that using show ip route command..

Again once you are in ISDN have u checked whether you are getting the required route for 3600 location ?

if possible do post out the config of 3600 and also the show ip route o/p of both 2600 and 3600 when its on isdn..

also throw some lite on the ip addressing scheme..

regds

Georg Pauwen · ‎11-15-2005

Hello,

in addition to Edwin´s post, can you try and remove all static routes, add two default statics with different administrative distances on both sides and advertise all interfaces in EIGRP ? So for your router Cisco2600, that would mean:

router eigrp 1

eigrp router-id 192.168.103.20

network 192.168.103.20 0.0.0.0

network 192.168.103.99 0.0.0.0

network 192.168.109.27 0.0.0.0

network 192.168.110.2 0.0.0.0

no auto-summary

!

ip route 0.0.0.0 0.0.0.0 Serial0/0

ip route 0.0.0.0 0.0.0.0 Bri0/0 200

Regards,

GP