You are implying the issue is with OpenBSD, because if you SSH into Linux first, the issue does not happen.
Send your pf.conf and your ifconfig - probably is an MTU or firewall issue, and others will be able to help with those. On Sat, Dec 14, 2024, 3:55 PM Lloyd <ng2...@proton.me> wrote: > I've a particularly vexing problem for which I've been unable to identify > the cause despite much research. > > There is an older Mac client on my network which experiences routine > packet loss when connected to OpenBSD boxes over SSH. This manifests as the > session "freezing" - text entered into a shell or text editor is > intermittently delayed by as much as 10-15s in some cases. It occurs with > such frequency the shell sessions become unusable. > > Initially I suspected a network issue. Packet captures on the client side > show many TCP retransmissions during the events. On the OpenBSD side, these > are identified as spurious retransmissions. I've checked and fiddled with > MTU, MSS, etc. to no avail. Examined routers, switches, SSH settings. It > does not matter if the client/server are on the same or different VLANs. > Multiple OpenBSD boxes are affected, running on different hardware > platforms, different hypervisors, etc. > > Now for the curve ball. I've a dozen Linux servers on this network and > none experience this issue at all. Furthermore, if I SSH into a Linux box > first, then SSH from there into the OpenBSD box, the issue goes away. > > Any ideas where I should look next? > > Regards > Lloyd > >
