*TOPS-20* The set of config files you need to edit in TOPS-20 is found here, about halfway down the page: http://www.ldx.ca/notes/tops-20-notes.html I'll paste it here: Configuring the system The *Panda Distribution* README has this to say about initial configuration: You?ll need to edit the following files. EMACS is installed on this system, along with TECO and EDIT. [More on these editors later.] SYSTEM:7-1-CONFIG.CMD to set your timezone SYSTEM:HOSTS.TXT to define your local host name and network SYSTEM:INTERNET.ADDRESS to define (again!) your IP address ? must be the same as in klt20.ini. Also define your netmask here as LOGICAL-HOST-MASK SYSTEM:INTERNET.GATEWAYS to define your IP gateway SYSTEM:INTERNET.NAMESERVERS Don?t bother with SYSTEM:INTERNET.NAMESERVERS. That is the configuration file for DEC?s resolver; although it?s simpler it has some interoperability problems with MMAILR which haven?t been resolved yet. SYSTEM:MONNAM.TXT to define your system name DOMAIN:RESOLV.CONFIG to define your DNS servers, your default domain (replacing MYDOMAIN.COM) and any users in addition to OPERATOR who can send control messages to the resolver. To actually edit any of those, you'll probably need to ENABLE first, eg: @ena $ The dollar-sign ($) prompt indicates that your privileges are enabled. *Linux Host* On the host side, I like to convert my ethernet to a bridge so I can add virtual interfaces easily. Here's the script I use (requires sudo, and that the user running it be in group adm, and that the tuntap devices be owned by and writeable by group adm): #!/bin/sh eth0text=$(/sbin/ifconfig eth0 | grep "inet ") HOSTIP=$(echo "${eth0text}" | awk '{print $2}') HOSTNETMASK=$(echo "${eth0text}" | awk '{print $4}') HOSTBCASTADDR=$(echo "${eth0text}" | awk '{print $6}') HOSTDEFAULTGATEWAY=$(/sbin/route -n | grep ^0.0.0.0 | awk '{ print $2 }') # Change as we add more guest OSes with network stacks _maxtap=2 # for i in $(seq 0 ${_maxtap}); do /usr/bin/tunctl -t tap${i} -u adam -g adm /sbin/ifconfig tap${i} up done # # Now convert eth0 to a bridge and bridge it with the TAP interfaces /sbin/brctl addbr bridge0 sleep 1 /sbin/brctl addif bridge0 eth0 sleep 1 /sbin/brctl setfd bridge0 0 /sbin/ifconfig eth0 0.0.0.0 /sbin/ifconfig bridge0 $HOSTIP netmask $HOSTNETMASK broadcast $HOSTBCASTADDR up # set the default route to the bridge0 interface /sbin/route add -net 0.0.0.0/0 gw $HOSTDEFAULTGATEWAY # # bridge in the tap devices for i in $(seq 0 ${_maxtap}); do /sbin/brctl addif bridge0 tap${i} /sbin/ifconfig tap${i} 0.0.0.0 done For some reason this seems to work even though that should be group netdev. I guess because "adam," who is running the emulator, owns the tun/tap devices. I have this in /etc/udev/rules.d/99_net_tun.rules: KERNEL=="tun", GROUP="netdev", MODE="0660", OPTIONS+="static_node=net/tun" I don't think that's standard; I think I added that at some point. And then in klt20.ini, I have a statement that looks like: devdef ni0 564 ni20 ifc=bridge0 ipaddr=192.168.248.249 dedic=false And then finally the dnpni20 executable is setuid root. All of this together gives me a TCP/IP stack on klh10 that allows the emulator to run as me, not as root, and bridges the TOPS-20 host into my real network. Adam