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> I've been trying to setup a VPN between the local network here and a few > roaming co-workers. The VPN went initially went up with no problems but I'm > finding it fairly difficult to use and I'm not sure even whether it's > OpenVPN's fault; I just don't have the tools to test things. > > I am able to ping across with no problems, and the other machine shows up on > my network neighborhood with no problems. > > However, the VPN was going to be used primarily for database protocols and, > while I am able to establish a database connection (most of the time) across > the gateway and do very simple queries, if I launch the full database > application it waits for about a minute before crashing out with "Database > connection unexpectedly closed". Database protocol uses TCP. With a window > open to the verb9 statuses, I see about a second of heavy activity after > which the packets drop down to their previous once-every-other-second rate. It sounds to me very much like a MTU problem. I had similar problems when I was using VTUN to bridge ethernets. I solved it by using linux TCP MSS adjusting to all bridged tcp sessions using the following command: iptables -A FORWARD -i br0 -o br0 -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1400 I think you have to use an even lower mss value with openvpn, as it has an even larger overhead than vtun (as default). You could also try adjusting the MTU with the build-in parameters in openvpn. /Mathias |