On 27 February 2018 at 12:17, Kip Warner <kip at thevertigo.com> wrote: [...]> I am having problems with already established connections to a remote > serverWhat platforms are the client and server?> timing out after a few minutes. I connect either over ssh or via > rsync tunnelled over the former. > > On the client side eventually I just see a whole pile of messages like > this, but no rsync traffic appears occurring: > > debug1: client_input_channel_req: channel 0 rtype keepalive at ope > nssh.com reply 1This sounds like some firewall or network device is aggressively timing out TCP connections. I suggest looking at the output of netstat at both ends when it starts sending the keepalive packets and finding the line corresponding to the SSH connection. If the "Send-Q" columns are non-zero and keep increasing it indicates that TCP is not getting acks for the packets it's sending. If that's the case you have a broken network or firewall of some kind. -- Darren Tucker (dtucker at dtucker.net) GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860 37F4 9357 ECEF 11EA A6FA (new) Good judgement comes with experience. Unfortunately, the experience usually comes from bad judgement.
On 27 February 2018 at 12:37, Darren Tucker <dtucker at dtucker.net> wrote: [...]> This sounds like some firewall or network device is aggressively > timing out TCP connections.Oh, one other thing I've seen cause this is a network device that does not understand TCP window scaling. You can test this theory by turning off window scaling (exactly how is platform dependent, but you only need to do it on one end) and reconnecting. If this works you still have a broken network device, but you have more information about the exact nature of the brokenness. -- Darren Tucker (dtucker at dtucker.net) GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860 37F4 9357 ECEF 11EA A6FA (new) Good judgement comes with experience. Unfortunately, the experience usually comes from bad judgement.