172.71.x.x is outside the range of 172.16 to 172.32 reserved for local intranets per RFC 1918, so is either in your allocated address space, or you are exposing your VMS system to the public Internet.
(Or you have a mis-configuration of your intranet)
If your system is exposed to the public Internet, with out a firewall, then you are going to get continuously probed for security holes. These probes can use up a lot of system resources, and might actually find a security hole, or if the attacker can not find a security hole, may try a DDOS.
I strongly recommend that you have some sort of firewall appliance that will handle the probes.
People on the comp.os.vms newsgroup may be able to offer more specific information about multinet.
malmberg December 12 2017 HPE only makes the most current version of OpenVMS Alpha / IA64 /VAX available to hobbyists. When I had access to the Alliance 1 program it was the same. No public downloads are allowed by HPE.
nmbonao December 08 2017 Is anybody knows OpenVMS 8.2 version downloadable version? or CD copy? Thank you very much
aarommes December 02 2017 Bitcoin and Blockchain enthusiasts ( plus distributed computing ) please connec / reply: http://www.openvmshobbyis t.com/forum/viewthread.ph p?forum_id=130&thread_id= 2991
malmberg September 10 2017 https://sourceforge.net/p /vms-ports/wiki/VMSInstal lation/ For the most part just use VMS 6.1 media instead of 7.3. But why run the older release?
DoeveR August 07 2017 Where can I find the write up on running VMS 6.1 using the simh emulator?
Bart March 20 2017 Happy to have found my password again!