Re: [Openvpn-users] why is SIGUSR1 required with ISDN dialup?

[Claas H. <cla...@ju...>]

> The SIGSUSR1 (or SIGHUP) closes and reopens the UDP socket -- which may be
> necessary when communicating over a connection-oriented link.  Probably
> some parameter in the IP stack which the UDP socket depends upon is
> timing out after 15 minutes.

What I don't understand is that a ssh session worked well over the isdn 
link. I started a ssh session and let the session alone for about 30 
minutes. The isdn link goes down. After the 30 minutes I issued a "ps ax" 
that worked after the connection come up again. The only thing is that it 
takes 1-2 seconds to bring up the link again. Maybe I should try to use 
openvpn with tcp instead of udp and see if this works.

> You might also try using the same lport and rport number -- doing so is
> usually necessary to get stateful firewalls to properly associate both
> directions of the connection.

There is no firewall between the two hosts.

> It is actually normal procedure for an OpenVPN tunnel over a
> connection-oriented medium such as ISDN to include something like
[ keep alive pings ]

The problem is that in this case the dialup line will never go done. The 
isdn link is dial on demand and sould only in up state when there's data to 
transfer. I tried diald to start openvpn only after the link goes up but it 
didn't worked for me.

Claas Hilbrecht