Everything installs fine and after some newbie problems with the L2TP tunnel, I'm having a good connection with my ISP.
I'd love to know how to make it work! I must be suffering from severe newbie-itis, since every time I try to bring a call up between two Linux boxen running L2TPD, the server blocks and won't even receive command messages.
Any hints on getting it working that far would be most appreciated. Anyone?
However, the VPN client refuses work. After running vpnclient the kernel reports: "unknown mac header length (8)" in the syslog.
Is the VPN client running over L2TP raw, or over the IP tunnel within PPP? Could you possibly be having a problem with exchanging certificates when the MTU of the IP-over-L2TP network is 1460 bytes (or less)?
The first thing I do with any upstream connection is set up a firewall rule to clamp the MSS to smaller than the MTU of the PPP link:
# Make sure path MTU works, even if not discovered.
$IPTABLES -I FORWARD -p tcp --tcp-flags SYN,RST SYN \
-j TCPMSS --clamp-mss-to-pmtuHTH Alex
