Network problems

[Dactyl]

At work we have a network with the following IP addresses:

192.168.0

.1 Router
.2 Comp1
.3 Comp2
.4 Comp3
.5 Comp4
.6 Printer
.7 Server
.8 Comp5

The setup:

All the Comps are basic work stations.
The "server" has the email server on it and the shared folders.
All the computers access the internet via the router.
Each Compx has an email address which the email server sorts for it.

This all worked hunkdory up until about 2pm this afternoon.

The problem:

The server cannot access the pop account and therefore cannot download any email. Also, none of the comps can communicate with email server software on the server.

However, all the computers, including the server, can still access the internet. And all the computers can still access the shared folder. However, when pinging either from the router or from any computer on the network, there is 100% packet loss.

So basically, the network works, the internet works. The computers can see each other and the router. All the computers can print. However, the email server software suddenly won't download email nor will any of the other computers from the server. I have rebooted and reset the router and reinstalled the server software to no avail.

This driving me insane, any suggestions?

[Lachrymose]

I'm not a network guru by any means, but could it be a DNS problem?

[Not_Done_Living]

if it's a dlink router.. reboot it.

I have similar issues once in a while..

[FormicaArchonis]

Originally Posted by Dactyl

However, all the computers, including the server, can still access the internet. And all the computers can still access the shared folder. However, when pinging either from the router or from any computer on the network, there is 100% packet loss.

So basically, the network works, the internet works. The computers can see each other and the router. All the computers can print. However, the email server software suddenly won't download email nor will any of the other computers from the server.

So what your saying is that all the connections work, but ANY ping from ANY machine and ANY request to download e-mail, even the server grabbing it from your ISP, fails?

Last time I did any major network work was 10BASE2 ethernet, but I'll give it a try. What firewalls do you have set up? Generally when some protocols get through but others don't it's because a firewall is stopping it.

Oh yeah - one more thing. Any info to be seen by using TRACERT to find the block point?

[Dactyl]

Originally Posted by Not_Done_Living

if it's a dlink router.. reboot it.

I have similar issues once in a while..

I have not only rebooted the router but also reset it to factory settings and re-entered all the information.

Originally Posted by FormicaArchonis

So what your saying is that all the connections work, but ANY ping from ANY machine and ANY request to download e-mail, even the server grabbing it from your ISP, fails?

Exactly.

Last time I did any major network work was 10BASE2 ethernet, but I'll give it a try. What firewalls do you have set up? Generally when some protocols get through but others don't it's because a firewall is stopping it.

I turned off all firewalls apart from the hardware one on the router. That will have to be my next step.

Oh yeah - one more thing. Any info to be seen by using TRACERT to find the block point?

Nope. I will look into that. Cheers.

[Dactyl]

For anyone interested the problem was McAfee blocking the ping and the email. This was quite impressive seeing as it had been uninstalled over a year ago, however, part of it remained and came to life to haunt me!

[UEL]

Yikes.

Makes me wonder about when McAfee comes pre-installed and expires. I usually uninstall it, but I wonder if something like this could still happen.