Between your library client computer and the internet there is on the library network a piece of software installed which channels all requests to the internet (probably for security reasons). You probably can't do much about it yourself.
- Try accessing pprune via direct IP-address (in case it's a problem with the domain name system, but I get a redirect to the DNS-address doing that):
http://67.201.16.181/
- Best solution: Get your problem known to the person responsible for the library computer network