Comment 26 for bug 638955

Emulated NIC is e1000.

I found out that if one reduces the MTU on the client like "ifconfig eth0 mtu 300" it seems ssh hangs much more rarely (but still hangs, at 300).
Reducing it on the virtualization host bridge is not enough though (unless you are initiating ssh from the virtualization host itself)
To trigger the hang, do:
while true ; do dmesg ; done
The higher the allowed MTU, the quicker the hang, e.g. MTU 500 hangs within one minute. 1500 hangs instantly.

Command line is the following. Excuse the length... it's a libvirt

LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin QEMU_AUDIO_DRV=none /usr/local/qemu-kvm-0.14.0/bin/qemu-system-x86_64 -S -M pc-0.14 -enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -name openindiana1 -uuid ed0b8483-d186-1f39-39ef-97194a1f02bf -nodefconfig -nodefaults -chardev socket,id=monitor,path=/var/lib/libvirt/qemu/openindiana1.monitor,server,nowait -mon chardev=monitor,mode=readline -rtc base=utc -no-acpi -boot c -drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive file=/dev/mapper/datavg1-openindiana1,if=none,id=drive-ide0-0-0,boot=on,format=raw,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,fd=54,id=hostnet0 -device e1000,netdev=hostnet0,id=net0,mac=52:54:69:b5:89:11,bus=pci.0,addr=0x3 -usb -vnc 127.0.0.1:0 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4

I'm available to try patches for a while if somebody can spot the problem... the host is still not in production.

Thanks for your work