VPN client connection failure "Reason 412"

[henrysacco]

I have a VPN 3000 concentrator and Cisco VPN clients installed for sales people who travel a lot. I am seeing many cases of connection failures "Reason 412"

Many of these problems are from hotels.

Can someone suggest to this novice the easiest way to troubleshoot? We have tried UDP,TCP and other combinations, but to no avail.

[aunraza]

This might be due to the NAT-T not configured on the concentrator. Usually if more than one person tries to connect from the same hotel, they're NATted out to the same IP, and unless NAT-T is enabled on the Concentrator, it won't work.

Configuration -> Tunneling and Security -> IPSec -> NAT Transparency. Check IPSec over NAT-T.

Hope this helps.

[laskew3]

AUNRAZA, is correct. I have run into the same issue. NAT-T solves this issue by encapsulating ESP within UDP.

Although I am sure you may have found it, or may have the issue resovled, I have provided the link for you that describes NAT-T.

http://www.cisco.com/en/US/products/hw/vpndevc/ps2284/products_tech_note09186a00800946af.shtml

Hope this helps..

[henrysacco]

I already had it enabled and it doesnt seem to be helping. Which logs should i be looking at to see why the client keeps getting disconnected?