1 /DECNET
/DECNET
/NODECNET
Directs LAT protocol to use the DECnet data link address (
/DECNET) or the hardware address (/NODECNET) when starting the
LAN controller. If you do not specify the /DECNET or /NODECNET
qualifier, the default is that the LAT protocol will use the
DECnet data link address.
Note that if you enter the CREATE LINK command with the /DECNET
qualifier and receive an error message indicating a "bad
parameter value," it means the SCSSYSTEMID system parameter is
set to an illegal value. To change the value of this parameter,
use the following formula:
(1024 * a) + n
In the formula, a is the DECnet area and n is the DECnet computer
number. If the value is outside the range of 1025 to 65535, the
LAT protocol cannot start.
When you use the /NODECNET qualifier, the LAN device driver code
determines which address to use. For example:
o If SCSSYSTEMID is set to 0 but DECnet is already running on an
Ethernet controller, the LAN device code allows LAT to use the
same address as DECnet (AA-00-04-00-xx-xx).
o If SCSSYSTEMID is set to 0 and DECnet is not running, the 08-
00-2B-xx-xx-xx address is used (a different address format is
used depending on the vendor of your LAN controller).
o If the setting for SCSSYSTEMID is the same as the DECnet node
number and DECnet is not running, the LAN device code forces
LAT to use the AA-00-04-00-xx-xx address.
If DECnet is configured on the system (or if the system is part
of a cluster), SCSSYSTEMID may contain a nonzero value. This
is a problem only when the system has 2 or more LAN controllers
connected to the same logical LAN.
For example, if your system has an FDDI controller and an
Ethernet controller, your site may be configured so that the
FDDI ring attached to the FDDI controller and the Ethernet
segment attached to the Ethernet controller are bridged by a
10/100 LAN bridge (FDDI-to-Ethernet). In this configuration, it
is impossible to run LAT over both controllers.
In such a configuration, you must run LAT and DECnet over the
same controller if SCSSYSTEMID is not 0. If you fail to do so,
DECnet starts first, which in turn causes the LAT startup on
the other controller to fail. This failure occurs because LAT
startup tries to use the AA-00-04-00-xx-xx address (the DECnet
LAN address) but is prevented from doing so by the data link
layer. The LAT startup fails because DECnet is already using
this address on a different controller. (In a single logical
LAN, all data link addresses must be unique. In this setup,
both controllers try to use the same address, which is then not
unique.)
The following command (which creates the LAT link) also fails
because the LAN driver tries to use the address based on
SCSSYSTEMID:
LATCP> CREATE LINK LAT$LINK_2 /NODECNET
If SCSSYSTEMID is set to 0, configuring LAT and DECnet on
different controllers is possible. However, in a cluster
environment, SCSSYSTEMID cannot be set to 0.
2 /DEVICE
/DEVICE=device-name
Specifies the LAN controller device name for a LAT data link (for
example, XEB0:). Only one LAT data link can be associated with a
LAN controller. If you enter the CREATE LINK command without the
/DEVICE qualifier, LATCP attempts to find an available controller
by using a list of possible LAT data link device names.
VSI advises that you specify a default device name by defining
the LAT$DEVICE logical name.
3 /LOG
/LOG
/NOLOG
Specifies whether LATCP displays a message confirming that
the link was created. If you do not specify the /LOG or /NOLOG
qualifier, the default is that no message will be displayed.
4 /STATE
/STATE=option
Specifies whether the link will be available for use. STATE can
have two options:
ON Specifies that the created link will be available for use
with the LAT protocol running.
OFF Specifies that the created link will not be available for
use.
If you do not specify the /STATE=option qualifier, the default is
that the created link will be available for use (ON).