Hi
Have just one Windows 2003 Server, two HP ProCurve 2650 switches stacked, one Zyxel ZyWall 35 Router/Firewall. Category 5 and 5e cables.
When more than 25 domain users go on the Internet, things get very very slow, and sometimes come to a standstill. It can appear as if the ISP has gone down.
Also, need an explanation for this. If the domain server goes down, people can't get out on the Internet. I don't understand why since the gateway should still be locally held until the lease expires, and the gateway is our firewall local IP address, not the servers. Why would this be happening, and I wonder if this problem is related to the one above?
One other thin (that may or may not be important / relevant to my problem) is that on the commander switch, I'm getting repeated errors of excessive CRC alignment errors on port 35, and "too many undersized/giant packets" error also on port 35. Don't know if this is relevant or not.
The main problem is the loss of Internet connection when several users are on. It's a 2 MB connection we have.
Port 35 could be going bad, or most likely a device with a bad NIC is attached. This is probably not causing your problem.
What type of internet connection do you have? Is this just web browsing that users are doing, or file transfers etc? You may want to try to monitor your external bandwidth that is being used. You can try MRTG if your WAN router supports SNMP to see what type of bandwidth is being used.