Question : Network Problem - Intermittent network failure

Hi, here is the problem.

I have a network with 4 servers:

1.  File and Exchange
2.  New SUN Accounting Server
3.  BES - Blackberry
4.  Old legacy SUN Server (Offline)

Recently the company decided to upgrade the SUN servers hardware, it was paging heavily etc.  This was done using imaging software as the application is a legacy one that would have been very difficult to install again.  The software used was called Acronis Enterprise Edition with Universal Restore.  We have used this product before with varying degrees of success.

During out of hours the old sun server was completely imaged and restored to the new server.  The new server came online, and is working fine.  The network configuration is identical and i cant see any reason to suggest this new server isnt working.  The old SUN server has remained offline, and unplugged just to make sure.

We are now experiencing very intermittent network failures.  Every 2-3 weeks the network esssentially goes down.  The desktops cant connect to the servers, not even with pings, and all external comms into the servers fails.  To get this back online i have had to essentially restart all servers and the switches.

We currently have a very simple network design, one switch downstairs which all the servers and firewall etc plug into and one upstairs for all the workstations, this connects down into the downstairs switch.  There is no reason to suggest a design fault in the switch setup or configuration as this has always worked in the past.  I have also replaced the downstairs switch with a new unit just to be sure.

We are stumped as to what this problem could be.  Sounds to me like some sort of IP conflict on the network etc, how can i find out what this problem is?  Its so intermittent as well which makes it hard to troubleshoot and find.

Would appreciate the help.  This is a big problem as i am sure you can understand.

Need anymore info, just ask.

Answer : Network Problem - Intermittent network failure

On the sun server, do you see nay error messages in /var/adm/messages file?