Also present on go version go1.7.1 windows/amd64

I have specifically allowed it in the firewall even though I am testing on the same physical machine. It makes no difference.

I can see no specific mention of it in my antivirus settings and would have no reason to suspect that as it will serve it up via the normal machine ip address but only if I specify it fully.

i.e.

http.ListenAndServe(":80", mux) only works on local host
http.ListenAndServe("192.168.1.83:80", mux) works but only for the specified ip address
http.ListenAndServe(":8080", mux) works as documented for any connection.

Um, is http:///ping even a valid URL for the http scheme? What does HTTP with no authority mean?

/cc @mikioh @alexbrainman

it seems that it has been edited out because I accidentally used formatting codes. Updated with more clarity.

If you say this works fine for port 8080 on your machine, but not port 80, then it sounds like something on your machine (firewall, anti-virus, as @minux suggested) is messing with you.

I'm pretty sure we already have unit tests for exactly this behavior, but if somebody wants to trybot a unit test in the net package listening on ":0" and then looking up the machine's IP addresses and connecting to all interface IP's on that port, and then us running the trybots, that would be interesting. (or we could even submit the test)

/cc @odeke-em who might be interested.

Ok you've won I'll give up and blame the firewall/antivirus and just use a different port.

Have you already tried to run "netstat -oan" before running your application?

I'm not a Windows user and have no Windows box, but when googling "windows+listen+port+80", I can see many articles such as "port 80 is used by system process." Seems like golang-nats or Stack Overflow is the best place for asking questions.