RE: options config...

[SBNelson,AT,thermeon,DOT,com]

> I spoke too soon.  I can ping Linux B from Linux A with no problems.
> However if
> I don't use the tunnel for a little while, I am unable to initiate a ping
> to
> Linux A from Linux B.  If I go back to Linux A and then ping Linux B and
> then
> try again from Linux B back to Linux A everything works.  Looks like Linux
> A is
> unable to initiate the tunnel.
> 
> Any ideas about why this is happening?
> 
Probably you are using your firewall to filter incoming packets so the
packets will only pass through if it the conversation is "established" and
since UDP is a connectionless protocol, there is a timer where after some
amount of inactivity the return packets are no longer considered as part of
an "established" conversation.

You will need to let ALL UDP packets for the appropriate port (from your
peer's IP address) through the firewall.