Routing problem in a GRE Tunnel

[Vangelis Komninos]

Hi everybody,

I would appreciate your kind help in a problem that we have:

Our setup

(My mobile)----(Telecom Provider) ------GRE tunnel---------<Serial0>-(Cisco 1941)-<Giga0/0 192.168.1.28>-------------<192.168.1.10 ethernet>-(Router)-<Serial 10.20.30.53>----Frame Relay-------<10.20.30.54>-(Router)-<192.168.3.1 ehternet>--------<192.168.3.2>-(IP Camera)

The short story:

We have a GRE tunnel with a telecom provider and we access our network through our mobiles. The main network is 192.168.1.0 and our base router is 192.168.1.10. Through frame relay we have connection with one of our sites in a subnet 192.168.3.0 and the router located at 192.168.3.1.

The problem:

Something is missing from 1841 (a route ?) and although I can connect to 192.168.3.1, I cannot connect to 192.168.3.2 or any other inside address.

*** The funny thing is when I trace ip 192.168.3.2 from the command line of 1941 everything is FINE ! So something is wrong with tunnel i suspect.

1841 setup:

interface Tunnel0

ip unnumbered GigabitEthernet0/0

tunnel source 172.19.255.46

tunnel destination 94.143.177.221

!

interface GigabitEthernet0/0

description $ES_LAN$

ip address 192.168.1.28 255.255.255.0

duplex auto

speed auto

no mop enabled

!

interface Serial0/0/0

ip address 172.19.255.46 255.255.255.252

no clock rate 2000000

!

ip route 94.143.177.221 255.255.255.255 Serial0/0/0

ip route 192.168.3.0 255.255.255.0 192.168.1.10

!----- This is the mobile range

ip route 192.168.30.0 255.255.255.0 Tunnel0

Best Regards

Vangelis Komninos

[Sandeep Choudhary]

I think your configration is correct ..no need to change .......

can you show me the interface from router 3......for the ip address 192.168.3.1........

comammnd:

sh int .....?

[Vangelis Komninos]

In Datus there is a section regarding the routing and addressing. This is it:

[FR_USER_GATEWAY]

Interface fru01

local_dte 405000001006004

local_ip 10.20.30.53 255.255.255.252

link athens

remote_dte 401000001006004

remote_ip 10.20.30.54

link_type pvc active 5

encapsulation snap

[END]

[ETH9]

ip_address 192.168.3.1 255.255.255.0

[END]

[IP_ROUTING]

ip route 192.168.1.0 255.255.255.0 10.20.30.54

ip route 192.168.30.0 255.255.255.0 10.20.30.54

[END]

And also in the central router the same section is like this:

[fr_user_gateway]

interface fru4

local_dte 401000001006004

local_ip 10.20.30.54 255.255.255.252

link sofico

remote_dte 405000001006004

remote_ip 10.20.30.53

link_type pvc passive

encapsulation snap

[end]

[eth4]

ip_address 192.168.1.10 255.255.255.0

[end]

[ip_routing]

ip route 192.168.3.0 255.255.255.0 10.20.30.53

ip route 192.168.30.0 255.255.255.0 192.168.1.28

[end]

Regards

[Sandeep Choudhary]

I am totaly confused..because:

on router 3(Datus router)

[ETH9]

ip_address 192.168.3.1 255.255.255.0

[END]

[IP_ROUTING]

ip route 192.168.1.0 255.255.255.0 10.20.30.54(It should be 53)

ip route 192.168.30.0 255.255.255.0 10.20.30.54(It should be 53)

[END]

and on router 2(Datus router)

[eth4]

ip_address 192.168.1.10 255.255.255.0

[end]

[ip_routing]

ip route 192.168.3.0 255.255.255.0 10.20.30.53(It sgould be 54)

ip route 192.168.30.0 255.255.255.0 192.168.1.28

[end]

[Vangelis Komninos]

Sorry I did a mistake in the frame relay ips. It was vice versa.

But I think this is minor since the channel from my mobile (192.168.30.91) till router3 (192.168.3.1) is working fine.

So the frame relay is functioning with no problems. Also since I am able to ping the router I presume that the path from my moble->telecom router->cisco 1941->router2->router3 is ok.

Also I could say that something is wrong in terms of routing if i couldn't ping the 192.168.3.2 from cisco command line.

But since I could, I believe that something is not properly configured inside the box (cisco) and specificaly from the tunnel side.

Thanks for your effort again!

Regards

[Sandeep Choudhary]

If the ip address are right then no problem....fram delay is working proerly.....

Now the point is ...you can reach till 3.1 but not inside..so i think ..its not the problem of tunnel.

so..now can you please tell me the interface of the router 3, where your camera ic connected..

example..like your camera is connected at fa0/0...then please show me the output of this command:

1. sh interface fa0/0(just check your interface on router 3)

2. sh interface tunnel0.................from the main 1941 router

Regards

Please rate if it helps.

[Vangelis Komninos]

router3 is located in a small vilage and is acting as the local gateway with the headquarters.

The local network is 192.168.3.0.

The router3 has a serial which is connected in frame relay and an ethernet port (192.168.3.1).

Camera is ip axis M-1031 and has ip 192.168.3.2 , gateway 192.168.3.1 and mask 255.255.255.0.

Also camera is connected in the same switch with the router.

So when I am at cisco command prompt, I can ping camera (192.168.3.2). This means that the path cisco->router2->router3->camera is accessible.

I hope I could describe my strange problem good enough.

Regards

[Sandeep Choudhary]

yes...I understand your problem.......

even i am in a big thinking process......because of strabge problem.......so just trying to find the cause:

Thanks for your quick replies....

please show output from your mobile:

traceroute 192.168.3.1

traceroute 192.168.3.2

Regards

[Vangelis Komninos]

  

[Sandeep Choudhary]

Hi ...

this output show that you can reach till 192.168.1.10...router after that ..no access.

Please check once again on your router 2(192.168.1.10):

the route shold be like this....if not there ..then please put this.

ip route 192.168.3.0 255.255.255.0 10.20.30.54

Regards

please rate if it helps

[Vangelis Komninos]

Thanks a lot for your help up to here, but this eoute seems to work fine since I can ping the 192.168.3.2 from cisco command line. Also I have access to this subnet (192.168.3.0) from my pc from central office so it's ok.

I know it is a headache but it is a real problem...

Regards

[Sandeep Choudhary]

so you reach this network(192.168.3.0) by your pc but not from your mobile?

[Vangelis Komninos]

Yes, that's why I suspect the tunnel as the cause of the problem.

Regards

[Sandeep Choudhary · Accepted solution]

no ...you can see your tracert to 192.168.3.2 from yor mobile......

you can reach till 192.168.1.10..but not further.....so....i dont think so ..it is a problem of tunnel.

can you try with another mobile or a pc ...and then tracert 192.168.3.2 or 3.57.

Regards

please rate if it helps.

[Vangelis Komninos]

Finally,

The tracert from iphone IS NOT working, but the ping works now!

During our tests somehow we solve the problem but we received wrong results since I was continue testing the connection with trace and not ping.

Thank you since it was a headache for me !!

Best Regards

[Sandeep Choudhary]

welcome and Thank you for your quick replies.

Enjoy

Regards