On Thursday, September 17, 2020 at 7:54:23 AM UTC+8 gneuner2 wrote:
> > That's true - Windows tries IPv6 first Windows does not try IPv6 first. Client applications that call `getaddrinfo` with `AF_UNSPEC` , ask for both IPv4 and IPv6 addresses when resolving names. When that happens, the resolver library (maybe on Windows only?) returns a list of IP addresses for that name, but puts IPv6 addresses first. The code than tries to connect to addresses in the order they are returned, meaning they try IPv6 first. If client applications would specify AF_INET instead for their `getaddrinfo` call, they would only get IPv4 addresses, but my understanding is that AF_UNSPEC is the recommended flag for new applications, and I think Racket is using it. I am not sure how things work on Linux with respect to address resolution, but on my windows machine, "ping localhost" receives responses from "::1" while on my RaspberryPi it receives responses from "127.0.0.1", even though I have the "::1" address for localhost as well. Strangely, it even responds from 127.0.0.1 when I ping "ip6-localhost" which is only listed as "::1" in my /etc/hosts file. Alex. > - but it isn't the whole story > here. If IPv6 were the only cause, then disabling IPv6 should fix the > problem ... but it doesn't always fix the problem. On some Windows > machines, name resolution by the local DNS client is just painfully slow > [and no one knows exactly why]. > > Certainly Stephen should try either binding the server to ::1 or > disabling IPv6 altogether ... but it's possible that neither of these > options may solve his problem. > > George > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/5c5e6d88-cbf0-4c15-b73a-9f9c4958b42an%40googlegroups.com.
