Dear all,
I have a network of nine 17.10 Ubuntu machines that connected with 3 Ethernet switches. A LAN line from a router is connected to the 3 switches that are connected to 9 machines, where each switch is connected to 3 machines.

However, sometimes the network got thrashed, whose cause is unknown, which required a reboot to all machines in order to bring them up. When the network is down, I can't ping from one the machine to the router because the router table and the ARP table are gone in all the machines.

How can I troubleshoot the cause of the thrashing? Is it better if I use routers instead of switches?

regards

No answers, but a few thoughts:

A web search tells me that "thrashing" is something that happens to a computer, not to an entire network. https://whatis.techtarget.com/definition/thrashing

Given that, could you describe the symptoms more fully and also describe what is happening when this problem manifests itself.

Have you checked the log files of the computers to try to identify which one might be the primary culprit?

It occurs to me that one test might be to reboot one computer at a time to try to identify the culprit. Another test may be to switch out the router, if you have a spare, since it is the only element in common with all nine machines.

Perhaps someone more knowledgeable than I will contribute some better ideas.

1 members found this post helpful.

so I looked at syslog, and I found bunch of errors from Synergy, a mouse sharing software. So I disabled all the Synergy daemons in all machines. Not sure if this is the root cause, but all I have to do is wait and see.

I'm closing this thread because I don't see the problem anymore since I disable Synergy

every other computer in my office network have connection to the internet but i dont.
My computer can ping the Router but cannot connect to the internet.
If i repair the connection, i will be prompted to get ip automatically if i activate this option, the internet will be rstored and later disconnect. This has been on for some time.
Is there any permannet solution this problem?