On Jan 16, 2014, at 12:18 PM, Bob Armstrong <bob at jfcl.com> wrote: Multinet is horribly unreliable because it is based on a fundamentally defective protocol design. Really ? I've been using it for years and haven't noticed this. Then you re very lucky. I had nothing but trouble. The reason is that Multinet uses the point to point mode of DECnet but over UDP. That clearly and explicitly violates several of the requirements of the DECnet routing architecture specification. The two main trouble areas are (a) packet loss UDP has it, point to point DNA datalinks do not; (b) lack of restart notification so if one side times out or otherwise restarts for some reason, there is a lot of back and forth before things finally sort out. GRE has none of this, because it uses the Ethernet datalink mode, which is the correct one to use for a datagram connection. In other words, the people who designed GRE tunneling understood DECnet, while the ones who created Multinet tunneling were either clueless or just didn t care that they were doing it wrong. paul