Network switch monitoring

Hi,

There’s been a few articles lately about network monitoring, but I still can’t solve my problem. Hopefully someone can help.

All our PC’s Internet access goes straight through the switch and out through the firewall. I.E. There’s no ISA server, although one server is running DNS on SBS 2003.

How do I monitor Internet traffic (websites visited, banwidth etc), as my firewall doesn’t have this feature?

Thanks.