My attempts to get onto www.radioshack.com come up with a 'Network Connectivity' error in the browser (both SeaMonkey, and Chrome). tracert got as far as my National Internet Backbone (22.214.171.124); then timed out.
Friends elsewhere in the country are able to confirm the radioshack website is up and running. Posting the URL in FB showed the correct preview; so it's probably the route followed by packets originating from my computer to the ISP.
Since my friends use a different ISP, I'm guessing their gateway is different too.
Is there a way to tell my modem/packets to go to a gateway other than that of my ISP?