Link to home
Start Free TrialLog in
Avatar of it-solutions
it-solutions

asked on

Cisco Router 881 VPN with Vodafone 3G Card

Hi experts,
we have setup an Cisco 881 an it works fine. Our problem is, if you try to build up a vpn-connection with a vodafone 3g card, the vpn-connection is established but you cannot ping our local network. I think it must be a problem with ipsec over UDP because Vodafone is doing IPSec over an adress translation. Has anyone solved the problem?
Avatar of Istvan Kalmar
Istvan Kalmar
Flag of Hungary image

Hi,

In this case you need to enable NAT-T on vpn concentrator!

Best regards,
Istvan
Avatar of Rick_at_ptscinti
Rick_at_ptscinti

just to be clear....you are trying to connect to the 881 remotely via the Cisco VPN client using a cellular connection on the host PC?
Avatar of it-solutions

ASKER

Hi, Thank you for your quick answers..

@Rick_at_ptscinti:
Yes, thats´s the case. If we connect whithout using the 3G-network it works fine.

@ikalmar:

Do you have a workaround to enable NAT-T on Cisco 881?
Isakmp nat-traversal 20 isn´t a valid command for this router.

Best regards,

it-solutions
try it:

crypto ipsec nat-transparency udp-encapsulation

But in this case you need to enable it on the central SITE!

Best regards,
Istvan
What do you mean with "need to enable it on the central site"?
ahh the central sit is the 881?
Yes, the central site is the 881, and we try to buildup a vpn-connection over vodafone 3g with Cisco VPN-Client 5.x.
ok...

in this case you need to enable nat-t:
crypto ipsec nat-transparency udp-encapsulation
but some ios it is defaultly enabled...

what shows the log on the router?
did you tried to debug?
deb cry isa
deb cry ips
Hello,

i debug, but there are no error messages. The connection is established, the VPN Client has got the IP-address 16.16.16.4, mask 255.255.255.0 and default gateway 16.16.16.1, but the local network 192.168.20.0 is not responding by ping.
The VPN works fine whithout using Vodafone as ISP.
I think vodafone blocking ESP?
ASKER CERTIFIED SOLUTION
Avatar of it-solutions
it-solutions

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Solution created in cooperation with Vodafone Business Support Germany