On Mon, Sep 21, 2009 at 12:49 AM, Ian Chard <ian.ch...@ict.ox.ac.uk> wrote: > Janne Johansson wrote: >> >> Ian Chard wrote: >>> >>> I'm troubleshooting a very strange problem, where my ssh connection to a >>> few different OpenBSD machines drops suddenly, with the client machine >>> receiving a TCP RST from the server. I've taken tcpdump captures on >>> both sides (in different sessions, so the tcpdump process doesn't die >>> with my shell), and the OpenBSD machine's capture doesn't log the RST it >>> apparently sends. >>> >> There are ISPs that "traffic shape" their links by killing long-lasting >> TCP streams by faking the RST in the middle. > > A good thought, and I've seen this myself. However, these connections can > drop after a second or two, and aren't traversing an ISP.
I've noticed a similar behavior, but not investigated to detail of using tcpdump, so my situation may very well be different. In my case, whenever I install a new snapshot one computer, i continue the rest of builds (ports mainly) via ssh sessions from another computer. In this case the two computers are connected via local unmanaged switch, and both computers have pf enabled. Nothing fancy with pf rules either. Often one of the two ssh sessions to the "freshly installed" machine will drop for no apparent (obvious) reason. As I said, I've not investigated using tcpdump as to what is causing the drops since the sessions sometimes remain alive forever, or drop after minutes or sometimes after a couple of hours. I've naively -- arguably incorrectly -- brushed this behavior off as something to do with the high load on the machine i'm building ports on. --patrick
