On Thu, Mar 18, 2021 at 2:49 PM Louis Guillaume <[email protected]> wrote: > > On 3/18/21 12:37 PM, RVP wrote: > > On Thu, 18 Mar 2021, Louis Guillaume wrote: > > > >> Ok - i did something similar with "nc" and text files in /var/log. It > >> is able to connect and transfer up to and no more that 6144 bytes > >> before closing. This seems to be consistent with what I was seeing via > >> ssh. > >> > >> Smaller files transfer completely, but anything larger than 6144b is > >> truncated at exactly 6144b == 6k. > >> > >> After some reading, that seems to smell like some kind of MTU or maybe > >> jumbo frame business. All systems here on on gigabit ethernet. Just a > >> hunch. Maybe it's my switch. > >> > > > > Try turning jumbo frames off--you don't really need it. Reboot the switch > > also. > > > >> I can't rule out the firewall (ipfilter) - but even if that is the > >> cause, this would be unexpected behavior. > >> > > > > Try a port (both on nc(1) and sshd) other than 22. > > > > -RVP > > Hrmpf - looks like jumbo frames are already off... > > wm1: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 > > ... also a tcpdump shows the largest packet size being 1500, so that all > seems in order. It does show the sshd sending an unexpected "RST" packet > right before the end, though... > > 192.168.1.2.22 > 192.168.1.126.64517: Flags [R], cksum 0xbd47 > > ... which leads me to think it's something with sshd now.
Before you go too far down a rabbit hole, you may want to swap-in a new cat6 cable. Jeff
