This happened to me after updating to 5.4 as well. Except mine have not come back. My OpenVPN configuration has been used for a couple years. This is what I am seeing in the log. TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity) TLS Error: TLS handshake failed > > I noticed that when I went over to CentOS-5.4 > on my server (and re-booted), > my openvpn connections failed for a couple of hours, > and then came back. > > Has anyone noticed this? > > What puzzled me was that the tun0 interface > was present on all machines (according to ifconfig) > but the connections seemed to be lost. >