[SOLVED] What is wrong with this network?

[Kittychow]

I have a few users that are losing their internet connection at random. These are newer Dell desktops connected from wall to IP phone to desktop cat6 wire. The computer is unable to ping one DNS server and the gateway. Can ping the main DNS server and other computers. The phone still works like normal. All of these systems connect to the same switch. I have tried the following. Plugged the computer directly into the wall. Set static IP, DNS, and Gateway. Flushed DNS cache, Updated system to the latest. Removed Drivers and reinstalled. Moved ports to another switch but they are all tied together. All other systems come though this switch including fiber from other buildings with problems. If this was DNS wouldn't more systems have this issue? Let me know if I can provide more detail.
Thanks

 

[Ralston18]

"From the wall" meaning an Ethernet wall jack - correct?

What specifically is that "IP phone" (make, model, etc.?) Does every desktop have that? Or are the Dell desktops sharing in some manner?

On one of the newer Dell computers run and post the results of "ipconfig /all" via the Command Prompt.

Using the same computer also run and post the results of "tracert 8.8.8.8".

 

[SamirD]

Sounds like you have a managed switch with some configuration or routing errors.

 

[kanewolf]

I agree with @SamirD To not be able to ping the gateway, that sounds like a problem with VLANs on a managed switch or similar.

 

[Kittychow]

Correct these are managed switches. Enterasys C5G124-48. The IP phones are Yealink t42S. I can not traceroute out to google's DNS because I am unable to ping the gateway.

 

[bill001g]

You really need to find some basic design documents or someone who knows how the network works.

There are way to many possibilities with fancy switches like those.

The switches can run either full layer 3 and act as the gateway or they can run layer 2 and run just the vlans. They can really be run in any combination of these modes and even then you could have a server or firewall acting as the gateway.

Not sure what to suggest if it is a small number of devices log on to each and pull the configurations off and then try to figure out how things are suppose to work.