Question Internal Network Keeps Blinking Out

[rrreed]

Hey everyone!

I have a problem that I'm looking to troubleshoot and I'm not sure where to start. We have a couple of servers that are separate from each other. The one is mainly used for front office work and is our Quickbook's server. The other houses our company database and we have large monitors around the office with in-house reports displaying on them, pulling data from this server.

At random times throughout the day, Quickbook users get booted out of the software and the reports on the monitors go blank. It's almost as if we lose connection for a moment but it's not felt anywhere else. I find it kind of strange that we're getting both servers knocked out at the same time. People browsing network files or even the internet don't seem to feel the effect. And I can click to refresh the report or login to Quickbooks and it will all load back up seconds after the issue without a fuss. Some days it never happens. Some days it will happen two or three times.

Any ideas on what this could be? I'm not sure if this is some kind of DNS server issue or a router issue? Everything in the building also goes back to a 24-port Netgear network switch that's fairly old. I'm not sure if that's going? I was hoping that someone might have an idea on what to look for.

 

[bill001g]

Not sure what it is but it is unlikely it is DNS or router.....but it can depend on the application and if it really just runs on the server or if it is talking to the internet.

In general if you have a local server and you use a switch like you do the traffic never goes to the router. You can actually turn off the router and the traffic will continue. Unless you have a local DNS server it is not likely a DNS problem. Traffic will not use a internet DNS server to resolve local machines. Even with a local DNS server you should not lose contact to it because again the traffic just passes between the device on the switch.

Do you have logs on your servers do they get any kind of error. All I can think of is you are losing the IP addresses because it times out or something or maybe there is a duplicate IP.

What I would do is on one of the server leave a constant ping run to the router IP. You don't have to use the router you could I guess use your other server. Mostly you need something that is running all the time.

It will be interesting to see if the server get ping loss at the same time you can't access the server. That would indicate a actual network issue.

Something like a duplicate IP is much more tricky to find. Sometimes the server will detect it and put a message in the event log if the server is windows based. This is kinda rare though someone would have to duplicate the servers IP. This is purely a guess. You hopefully get a clue from the server

 

[kanewolf]

Not sure what it is but it is unlikely it is DNS or router.....but it can depend on the application and if it really just runs on the server or if it is talking to the internet.

In general if you have a local server and you use a switch like you do the traffic never goes to the router. You can actually turn off the router and the traffic will continue. Unless you have a local DNS server it is not likely a DNS problem. Traffic will not use a internet DNS server to resolve local machines. Even with a local DNS server you should not lose contact to it because again the traffic just passes between the device on the switch.

Do you have logs on your servers do they get any kind of error. All I can think of is you are losing the IP addresses because it times out or something or maybe there is a duplicate IP.

What I would do is on one of the server leave a constant ping run to the router IP. You don't have to use the router you could I guess use your other server. Mostly you need something that is running all the time.

It will be interesting to see if the server get ping loss at the same time you can't access the server. That would indicate a actual network issue.

Something like a duplicate IP is much more tricky to find. Sometimes the server will detect it and put a message in the event log if the server is windows based. This is kinda rare though someone would have to duplicate the servers IP. This is purely a guess. You hopefully get a clue from the server

I agree, you probably need to setup a dedicated ping to each of your server IP addresses from one of your client workstations. See if the PING is ever interrupted.

 

[rrreed]

Not sure what it is but it is unlikely it is DNS or router.....but it can depend on the application and if it really just runs on the server or if it is talking to the internet.

In general if you have a local server and you use a switch like you do the traffic never goes to the router. You can actually turn off the router and the traffic will continue. Unless you have a local DNS server it is not likely a DNS problem. Traffic will not use a internet DNS server to resolve local machines. Even with a local DNS server you should not lose contact to it because again the traffic just passes between the device on the switch.

Do you have logs on your servers do they get any kind of error. All I can think of is you are losing the IP addresses because it times out or something or maybe there is a duplicate IP.

What I would do is on one of the server leave a constant ping run to the router IP. You don't have to use the router you could I guess use your other server. Mostly you need something that is running all the time.

It will be interesting to see if the server get ping loss at the same time you can't access the server. That would indicate a actual network issue.

Something like a duplicate IP is much more tricky to find. Sometimes the server will detect it and put a message in the event log if the server is windows based. This is kinda rare though someone would have to duplicate the servers IP. This is purely a guess. You hopefully get a clue from the server

We do have in-house DNS servers. I am running a ping test on these other two servers currently. Of course, today nothing happened but I'll continue to keep track and let you all know what I find. Thank you for your input! It's super appreciated!