It depends on your OS and on the program. A program needs to correctly use getaddrinfo() for addresses passed in. When that is done all should work like a charm as getaddrinfo() will handle the scope. PuTTY for instance does this. As you are discussing URL's though, it is nearly impossible to use scopes in there, as %en0 on one host will be completely different on another. Thus it only has limited use for URL's and can in effect only be used to access a host directly. http://[fe80::230:65ff:fed6:b164%en0]:80 Should work for your computer, that is if that address really has a webserver running. Bonjour/LL-DNS/MDNS/uPNP and similar systems is the right way to go. For 'routers' (currently those boxes which do your IPv4 NAT) it is expected that they provide that kind of functionality and/or that they will be doing ULA's, which they automatically generate and RA on the local network.