NAT-T Unhandled UDP encap type: 1

["Lewis Shobbrook" <lshobbrook@fasttrack.net.au>]

Has anyone seen this before?

.... udp_encap_rcv(): Unhandled UDP encap type: 1

I'm attempting to configure a NAT-T freeswan, XP L2TP connection, which
fails and leaves the above entry in the logs and also ... Quick Mode I1
message is unacceptable because it uses a previously used Message ID
0x968d642 in the auth.log

I'm using the native ipsec stack in Debian unstable 2.4.25-1-686 kernel
with Debian freeswan release 2.04.

I can successfully create a pure IPSEC connection, but have experienced
authentication issues when using cached domain profiles on the 2K/XP,
which are averted with the native L2TP/IPSEC.

Any ideas appreciated...

Cheers,

Lewis Shobbrook