Random client connection loss

[machineswalkamongus]

I've a problem with OpenVPN (which is running on an IPFire), it's randomly losing the connection with a client. Currently I'm experiencing this random connection loss only with host-2-net.
I'm also running a few net-2-net connections, which are running without any problems.
The server is managing around 15 clients, which all experience this problem. So far it seems to appear absolutely randomly, in idle or under load, after a few mins or after hours, it doesn't matter.
The error message is unfortunately with little information regarding the source of the connection loss,

the first error message is:

Code: Select all

read TCP_CLIENT: Unknown error (code=10060)

and the second one:

Code: Select all

TCP: connect [AF_INET]xxx.xxx.xxx.xxx:1194 failed: Unknown error

The client config (which is generated by IPFfire) looks like this:

View OriginalClient Config

#OpenVPN Client conf
tls-client
client
nobind
dev tun
proto tcp
tun-mtu 1400
remote xxx.xxx.xxx.xxx 1194
pkcs12 OpenVPNTest.p12
cipher AES-128-CBC
comp-lzo
verb 3
ns-cert-type server
verify-x509-name xxx.xxx.xxx.xxx name

Maybe someone else already encountered this kind of problem?
Help would be appreciated, thanks!