I would also like to run multible instances of simh. This works fine for me as long as only one of them tries to do networking. Once I attempt to start networking on a second instance, the networking on the first instance stops working. This makes it difficult to run a vaxcluster on my alpha :-( How are the simh instances sharing the Ethernet interface? I don't really know. It appears a new EWA pseudodevice is created for each instance. However, PCAP-VMS seems to require the pseudodevice to be in promiscuous mode and I suspect that this is only allowed for one of them. It's not clear to me whether networking is even supposed to work for multiple instances. I should try installing an extra ethernet adapter and see if that allows it to work. Regards, Peter Coghlan.