Sent from my iPhone On 10 Nov 2013, at 12:08, "Bob Armstrong" <bob at jfcl.com> wrote: It s not exactly a DEC problem, but I know there are several people on HECnet running simh under Linux and I m hoping somebody has already figured this one out. I used to run simh (vax and pdp11 both) under Ubuntu 10.04 using Johnny s bridge program and a tap device to connect to HECnet. sudo tunctl -t tap0 sudo ifconfig tap0 up sudo -b /usr/local/bin/hecnet-bridge 4711 the bridge.conf file (I ll post it if anybody wants) bridges tap0 with Psilo.update.uu.se and in simh I would say set xqb enabled attach xqb tap0 and it worked great. Everybody was happy :-) BUT, now I ve upgraded to Ubuntu 12.04 (Ok, I m not an early adopter!) and, as you might guess, it doesn t work anymore. No errors and the tap0 device looks OK bob at falsetto:~/legato$ ifconfig tap0 tap0 Link encap:Ethernet HWaddr c6:36:37:eb:16:7a UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) but nothing ever happens. No data seems to pass between the bridge program and simh. Is anybody else using Ubuntu? Did you run into this problem? Thanks, Bob Try setting the interfaces promiscuous.