I'm a n00b, and I've spent some time trying to research this without finding a good answer. I'm posting my notes in case they are helpful for someone...
In C one would use [getaddrinfo](https://archive.fo/eFztO#selection-589.810-589.883). This is much easier in Python, which has a high-level [getsocketinfo wrapper](https://hg.python.org/cpython/file/3.5/Modules/socketmodule.c): #!/usr/bin/python3 import socket host = 'www.kame.net' port = 80 family = socket.AF_INET6 type = socket.SOCK_STREAM addrInfo = socket.getaddrinfo(host, port, family, type) print(addrInfo[0][4][0]) Run Nim doesn't seem to have an equivalent portable high-level getaddrinfo. import net, osproc, posix, strutils, nativesockets proc getIpv6_execCmd(hostname: string): string = ## Would only work on UNIX with https://linux.die.net/man/1/host const lookupCmd = "host -t AAAA " expectStr = " has IPv6 address " let (output, err) = osproc.execCmdEx(lookupCmd & hostname) let expectPos = output.find(expectStr) if expectPos < 0: return "" let startPos = expectPos + expectStr.len let finalPos = output.len - 2 if finalPos <= startPos: return "" return output[startPos..finalPos] proc getIpv6_dial(hostname: string): string = ## Don't know why this doesn't work... {{{Error: unhandled exception: ## Additional info: "Servname not supported for ai_socktype" [OSError]}}} let s = net.dial(hostname, 80.Port, Protocol.IPPROTO_IPV6) return s.getLocalAddr[0] proc getIpv6_socket(hostname: string): string = ## Also doesn't work... {{{Protocol not supported}}} let sock = newSocket(Domain.AF_INET6, SockType.SOCK_STREAM, Protocol.IPPROTO_IPV6) return sock.getLocalAddr[0] proc getIpv6_getaddressinfo(hostname: string): string = ## Don't have time to figure this out tonight... const fam = Domain.AF_INET6 var addrInfo = getAddrInfo(hostname, 80.Port, fam) echo addrInfo.ai_addr.sa_data.addr result = "" while true: var outBuf = newString(64) let dataAddr = addr addrInfo.ai_addr.sa_data let r = inet_ntop(fam.cint, dataAddr, addr outBuf[0], 65'i32) result &= outBuf if addrInfo.ai_next.isNil: break addrInfo = addrInfo.ai_next freeAddrInfo addrInfo echo getIpv6_getaddressinfo("www.kame.net") Run
