On Wed, Sep 25, 2019 at 2:57 PM Matthew Flatt <mfl...@cs.utah.edu> wrote: > > At Wed, 25 Sep 2019 12:49:36 -0400, David Storrs wrote: > > 1) Is it possible that there is a bug in the underlying C code? > > It's always possible. But if I understand the original problem, it > seems unlikely that a bug manages to exactly reconstruct a port number > that has been replaced in a UDP packet by a NAT. > > > Just to make sure we're talking about the same thing, I'm enclosing > complete code based on your fragments. If I run "server.rkt" first and > then "client.rkt", I see > > me: 0.0.0.0 25891 > reply from: ZZZZ 54545 > reply: #s(transport-address "XXXX" YYYY) > > If I run as-is, using "localhost" as the server shown by ZZZZ, then > XXXX and YYYY are `127.0.0.1` and `25891`, as expected. I change > "client.rkt" to connect to a remote host where my client is behind a > NAT, then XXXX is my NAT's address and YYYY is something other than > 25891 --- and that YYYY persists over multiple runs of "client.rkt" and > "server.rkt" in some complicated way that does indeed seem to be at > least tens of seconds. (My NAT is an AirPort.) > > If I understand, you're seeing YYYY as always 25891, and you have good > reason to think that the NAT isn't just using 25891 as a convenient > substitute for 25891. I have no explanation.
Interesting. When I run server.rkt and client.rkt on my local machine then I, like you, get 127.0.0.1 and 25891. When I put the code onto my AWS instance so that there is NAT between us, I *still* get 25891 on both the server and the client. If it's working for you then there must be something wrong with my network. Would it be possible for you to give me the IP of the remote machine you used and leave server.rkt running there for an hour or so? That way I could try it against a different remote machine without needing to spin up and provision a different VM. -- 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/CAE8gKofbzFPg%3D-bwQeaBX6H-QaJCvp1Cu-q_M3iQi66oPF_8vA%40mail.gmail.com.
