Here's what I did to get DECnet running on my TOPS-20 system (Panda distribution).
1) Preconfigure the Ethernet interface with the right MAC address with ifconfig xxx ether
aa:00:04:00:xx:xx
2) Set the interface in the klt20.ini file accordingly:
devdef ni0 564 ni20 dedic=true ifc=e1000g1 enaddr=aa:00:04:00:2e:4d
3) In SYSTEM:7-1-CONFIG.CMD I have these lines:
NODE CALHAN 19.302
ETHERNET 0 DECNET
DECNET ROUTER-ENDNODE
DECNET MAXIMUM-ADDRESS 1023
4) For the node database, I'm using SYS:SETNOD.EXE. Run that, then use SET NODE
commands to populate the database (a "TAKE" script can be quite handy) and then
SAVE to a binary database.
At bootup, run SETNOD and issue the commands GET (to read the binary database) and
then INSERT (to load the node database into the monitor).
I believe that's it for getting it to speak DECnet reasonably well.
--Marc