Connection lost when doing rsync over openvpn

[gxcr]

Hi, I have configured Ubuntu server on an old machine for serving as an offsite backup. The machine act as a vpn client and can connect successfully to the server. At the server I run a cron job every night, to rsync any changes in samba shares to the backup machine over the openvpn tunnel. The problem is that the connection is lost in the ethernet interface (however ifconfig show that the link is up and configured properly) when rsync is working. I have searched in /var/log/messages and /var/log/syslog but haven't found something unusual.

Some complementary information:

1. When openvpn client is down i can ssh to the machine ethernet ip address without problem. When openvpn client is up i can only ssh to the tun ip address.
2. There is a known issue with the ethernet chip VIA VT6102 of the machine, that produces connection problems. I have put acpi=noirq in grub boot options without making any difference. When there is no rsync job executing the link is up for hours.

Please if someone can enlight where the problem may arise, it will be a great help.

Thanks in advance and sorry for my English.

[gxcr]

Yesterday i noticed a new disconnection, this time without doing rsync. Today i have verified the dates of both server and client (both synchronized with ntp) and noticed that openvpn server is one hour late. This issue was produced for a recent modification of DST policies in my country. I have patched the timezone and will test is this is the cause of the desconnection.

It's possible that the openvpn link get broken if server and client change their dates after the connection has been made?

Thanks in advance.