Note

First of ou will not be able to access proxy service from BNL (they are all blocked) but the best ways to check if a site is blocked or up (in another country, while you are visiting for example) would be to use one of those services. They re-pipe the pages for you and you may be able to see the result safely.

Tools

Otherwise, you can use  a lower tech check BUT please, check with more that one service (the reason is that in cases where DNS is a mess, some services may have the updated IPs, some not). Here are sites you may use:

• CheckSite.us - simple interface, can also access directly the site you are looking for with a URL like http://www.checksite.us/?url=MyURL.I.Want.to.check (example: http://www.checksite.us/?url=www.star.bnl.gov)
• IsUp - this site is simple and can also be used with a direct URL check like http://www.isup.me/MyURL.I.Want.to.check (example:  http://www.isup.me/www.star.bnl.gov)

Hope this helps.

More advanced

Well, there is always the Creating an SSH tunnel in Linux trick to another computer located at a remote location.

Disclaimer: Use of such measures to circumvent security may not be acceptable at all sites.