The Question is:
What causes this? It happened for a period of about 15 minutes recently.
The Answer is :
DECnet host 1.140 sent a message to LOCAL:.FROD01 with CSMA-CD protocol
type 00-18, and host LOCAL:.FROD01 did not know what to do with it.
If the remote host is running OpenVMS, you can use SDA (ANALYZE/SYSTEM)
to examine the protocols active on the remote network controller, in an
effort to determine which remote application is associated with 00-18
on a remote network controller.
Of 'AA0004008C04AA0004008D040018'H, the key pieces here are the address
field 'AA0004008C04' and the protocol field '0018'. The protocol field
is obvious. To convert the address field (AA-00-04-00-8C-04) here, use
the last two bytes (8C04) -- reversed (048C) -- as the DECnet Phase IV
address. The value can then be converted to the DECnet Phase IV address
using the same scheme as described in the FAQ for converting the system