+ 0 Votes When you plug directly into the switch, wizard57m-cnet Moderator May 29, 2013 at 12:33pm PST you are sort of making a "new" internet connection, and you may have to setup this connection in your operating system's settings, so that it doesn't think you are still connected via the firewall. + 0 Votes Reponse To Answer CG IT May 31, 2013 at 12:53am PST routers create networks. Each router has it's own subnet addressing and default gateway. Disconnecting your Linksys router, which is the gateway for all hosts behind it, means host's can't find the gateway out. The hosts don't know about the Cisco router as a gateway out because their gateway address is the Linksys. Thus no internet. + 0 Votes It's All Numbers info May 29, 2013 at 11:22pm PST If your ISP has provided you with a router, and not simply a 'modem', then the IP addresses are probably wrong. I'm betting the 'Internal' IP address of the ISP's router is different than the one your Linksys used. Since the computers are probably all still pointed at the Linksys' old address as their gateway, they now don't know where to go... + 0 Votes More info would help Charles Bundy Updated - May 30, 2013 at 2:47am PST e.g. traceroute with & without BEFSX41 inline. But at a guess I'd say the Cisco 2400 IAD is setup to route a static IP (single) w/o NAT. Thus only one of your devices connected to your HP Procurve switch would have Internet access assuming it matches that IP (which depending on your DHCP/IP setup is unlikely. Guessing it is a completely different subnet.) The BEFSX41 is more than likely providing the NAT to single IP for the Cisco IAD 2400. For that matter it may be providing DHCP as well. + 0 Votes did you powercycle the ISP's modem markp24 May 30, 2013 at 3:52am PST I have had situations where all i had to do was power cycle the isps modem when connecting a new internal router. If that doent resolve it, then i agree with the prior pose if checking you ip addressing setup on the router and any DHCP services you may have seup, try to match it to the old router the best you can (where applicable). + 0 Votes Answer to clarification stepsimon May 30, 2013 at 4:06am PST Basically it amounts to doing what my boss suggested. We'd been having a problem with our email and she wanted me to try bypassing that firewall, so I tried it and found something I didn't understand. + 0 Votes Thanks. stepsimon May 30, 2013 at 4:10am PST The ISP's router not matching the NAT IPs from behind the Linksys makes perfect sense to me. Thank you very much.