Re: Some odd TCP behavior (timeouts)

From: Michael Tuexen <tuexen_at_freebsd.org>
Date: Wed, 19 May 2021 21:15:05 UTC
> On 19. May 2021, at 19:40, Jens Schweikhardt <schweikh@schweikhardt.net> wrote:
> 
> Hello, 
> 
> I'm having a TCP connectivity issue stumping me and driving me crazy.
> The TLDR version: No more printing on my LaserJet (but ping works),
> while printing and the web interfacw works fine under Windows.
> Other TCP connections apparently flawless.
> Wireshark shows FreeBSD performing the three way handshake but
> then ignoring some packets sent from the printer (no ACKs)
> and retransmitting until timeout hits.
> 
> The details with the wireshark logs are on 
> https://superuser.com/questions/1649435/mysterious-tcp-http-issue-accessing-laserjet-web-interface
Hi Jens,

I only see screen shots, but not a link a the actual log files. Could
you share the a .pcap or .pcapng file? You can send them to me via e-mail,
if you prefer.

Best regards
Michael
> 
> I have seen a few commits to CURRENT's tcp and timeout code recently.
> I went back to stable/13 as of two days ago, but still no joy.
> 
> Has anyone else noticed something going on with TCP?
> Especially HTTP/HTTPS, like connections timing out in rare cases?
> If you have a LaserJet (preferably 551dn), can you still access
> its web interface, or get a reply with
> 
> printf "GET / HTTP/1.0\r\n\r\n" | nc LaserJet 80   # or 443.
> 
> Regards,
> 
>       Jens
> -- 
> Jens Schweikhardt http://www.schweikhardt.net/
> SIGSIG -- signature too long (core dumped)
>