Failure to net boot a MicroVAX II

I have been trying to boot my MicroVAX II over the network off a SIMH boot node. This is what I get on the boot node: %%%%%%%%%%% OPCOM 26-AUG-2013 13:16:56.14 %%%%%%%%%%% Message from user DECNET on VX3900 DECnet event 0.3, automatic line service Circuit QNA-0, Load, Requested, Node = 5.24 (MICRO4) File = DISK$VAXVMSRL054:<SYS18.>, Operating system Ethernet address = 08-00-2B-04-AE-54 %%%%%%%%%%% OPCOM 26-AUG-2013 13:17:01.15 %%%%%%%%%%% Message from user DECNET on VX3900 DECnet event 0.3, automatic line service Circuit QNA-0, Load, Successful, Node = 5.24 (MICRO4) File = DISK$VAXVMSRL054:<SYS18.>, Operating system Ethernet address = 08-00-2B-04-AE-54 %CNXMAN, Received VAXcluster membership request from system MICRO4 %CNXMAN, Proposing addition of system MICRO4 %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:19.15 %%%%%%%%%%% 13:21:19.15 Node VX3900 (csid 00010001) received VAXcluster membership request f rom node MICRO4 %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:19.15 %%%%%%%%%%% 13:21:19.15 Node VX3900 (csid 00010001) proposed addition of node MICRO4 %CNXMAN, Completing VAXcluster state transition %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:19.80 %%%%%%%%%%% 13:21:19.80 Node VX3900 (csid 00010001) completed VAXcluster state transition %CNXMAN, Lost connection to system MICRO4 %PEA0, Port has Closed Virtual Circuit - REMOTE NODE MICRO4 %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:34.78 %%%%%%%%%%% 13:21:34.78 Node VX3900 (csid 00010001) lost connection to node MICRO4 %CNXMAN, Timed-out lost connection to system MICRO4 %CNXMAN, Proposing reconfiguration of the VAXcluster %CNXMAN, Removed from VAXcluster system MICRO4 %CNXMAN, Completing VAXcluster state transition %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:54.30 %%%%%%%%%%% 13:21:54.28 Node VX3900 (csid 00010001) timed-out lost connection to node MICRO4 %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:54.30 %%%%%%%%%%% 13:21:54.28 Node VX3900 (csid 00010001) proposed reconfiguration of the VAXclust er %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:54.30 %%%%%%%%%%% 13:21:54.28 Node MICRO4 (csid 00010004) has been removed from the VAXcluster %%%%%%%%%%% OPCOM 26-AUG-2013 13:21:54.31 %%%%%%%%%%% 13:21:54.28 Node VX3900 (csid 00010001) completed VAXcluster state transition I am using a DEQNA and booting off SIMH running VMS 5.4. This has worked fine for me multiple times before without issue. I have just tested both a VAX 4000-200 and a MicroVAX 2000 (over thinwire, very slow to boot) and they both boot fine, so I don't think there is a problem with the boot node or the network. I have tried replacing the cabinet kit (this is the same machine where I have been having the cabinet kit problems), the AUI converter, the patch cable, the DEQNA with another DEQNA and also with a DELQA. The result is always the same. I am not sure what the problem might be. I suppose it could still be something at the network level. It might perhaps be the CPU board, but if it gets that far into the boot sequence (already prompted for date and time) this seems unlikely. Any suggestions? Regards Rob