[Openswan Users] Problem with L2TP / Transport mode

[Mark van Proctor]

In regards to this matter, I did some further snooping around and have found
the following messages coming up in a tcpdump on the external interface:

IP <client machine> > <local machine>: ESP(....)
IP <local machine> > <client machine>: icmp 152: <local machine> udp port
l2tp unreachable

Normally, I would see the following, even if the packet is eventually logged
and dropped by the firewall:

IP <client machine> > <local machine>: ESP(....)
IP <client machine>.<client port> > <local machine>.<local port>: ....

So to me, this looks like 26sec is basically saying that the l2tp data is
not valid for the tunnel.
Setkey -DP shows the correct tunnels for port 1701:

<client IP>[1701] <external IP>[1701] udp
	in ipsec
	esp/transport//unique#xxxxx

<external IP>[1701] <client IP>[1701] udp
	out ipsec
	esp/transport//unique#xxxxx

Any other thoughts?

Thanks,

Mark