Frequent connection loss in CentOS 5.5

Question

I have a CentOS 5.5 x64 server setup on a Intel Xeon based machine, For panel, I have installed VirtualMin.

I'm facing a weird network problem, with following symptoms:

1. When SSH-ing to the machine, or connecting via VNC it oftens says "connection reset by peer"
2. Also sometimes is does connect, but it resets the SSH machine identification (the RSA) everytime.
3. Even if sometimes it does connect, the password is not accepted.

1/10 chances I can get into the machine, then it stays like that for a considerable time.

The IP is static, and the router also has the DHCP pool configured so that the IP is not assigned to any other machine.

Answer 1

Define the problem: L2/3 or L7 Use ping when network problem

Use packet sniffer tcpdump can help you find the problem

Use monitoring system nagios/zabbix will help determine the frequency of problems

Read log they often contain useful information

Answer 2

It was a issue with DHCP settings in the motherboard BIOS (very weird). Apparently assigning static IP in the BIOS is pretty unreliable, if routers refuse to assign the requested static IP.