User manual

Microsoft Windows™
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To create single-interface set-up, edit your VAX MP startup script to attach host interface to VAX MP
virtual network adaptors as needed, for example:
set xq enabled
set xq mac=08-00-2b-aa-bb-c1
set xq type=delqa
attach xq Marvell Yukon
You can also refer to host network adapters in the attach command by their UUID-based names, i.e. in
format
\Device\NPF_{UUID}.
Only Ethernet NICs and virtual Ethernet adapters such as Microsoft Loopback Adapter can be attached
to XQ or XQB for mapping virtual DEQNA or DELQA adapter. Host WiFi interfaces might superficially look
similar to Ethernet interfaces but they are actually not Ethernet and cannot be used for VAX MP or SIMH
Ethernet networking.
By the way of example, let us say XQ is bound to the host machine’s Ethernet adapter, and this host
adapter is assigned IP address 192.168.1.100. Then when configuring TCP/IP Services for OpenVMS you
can define interface QE0 (bound to XQ) to have IP address 192.168.1.200:
$ TCPIP SET INTERFACE QE0 /HOST=192.168.1.200
$ TCPIP SET CONFIGURATION INTERFACE QE0 /HOST=192.168.1.200
Depending on exact value of network addresses you actually use and network topology it may be
necessary to additionally specify options
/NETWORK_MASK=x.y.z.w and /BROADCAST_MASK=m.m.m.m.
Both host machine and VAX MP are connected to the physical wire by host’s NIC they share. Host OS will
generally utilize the network card to send Ethernet packets with sender’s MAC address field in the
packet set to the physical card’s own MAC address. Whereas VAX MP will be sending Ethernet packets
with sender’s MAC address field set to MAC address of virtual adapter defined in startup script (e.g. 08-
00-2b-aa-bb-c1 in the example above).
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In addition, VAX MP will be sending IP packets with sender’s IP
address set to 192.168.1.200, whereas host OS will be sending as 192.168.1.100.
Thus even though host OS and VAX MP share the network card, they will be sending Ethernet packets to
the wire as two different machines.
On the receiving side, since VAX MP puts the card is in promiscious mode, both host OS and VAX MP’s
virtual DELQA controller will receive all packets on the wire sent by other hosts. They will filter the
packets and process only those packets that they need, i.e. host OS will generally pick up the packets
destined for the card’s MAC address (and for IP 192.168.1.100) whereas VAX MP will pick up the packets
destined for DELQA virtual MAC address (and IP 192.168.1.200). Packets that were broadcasted to the
subnet or sent to any matching multicast address will be picked up by both host OS and VAX MP.
Thus even though host OS and VAX MP share the network card, they will effectively be both sending and
receiving Ethernet packets to/from the wire as two different machines.
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DECnet and VAXcluster protocols will further change effective MAC address to the value in range
AA-00-04-00-xx-yy derived from DECnet node number and SCS ID.