IPSec passthrough problems

Hi All,

I'm having some difficulty in establishing a VPN connection to my work LAN.

I'm using the cisco vpn client to connect to a cisco vpn concentrator using UDP IPSEC through an e-smith 5.6 box.
In the client there are two settings for the VPN connection, tcp and udp. tcp works fine (my college uses the tcp option and this connection works like a charm), my work however uses the udp encapsulation option and this one doesn't work.

Has anyone encountered this problem before?

Thanks in advance,

Michiel