z/VM: CP Commands and Utilities Reference - z/VM - IBM

DEFINE LAN
170 z/VM: CP Commands and Utilities Reference
The Class B form of the command also accepts OWNERid SYSTEM (creating a
PERSISTENT LAN), or any other user ID (creating a TRANSIENT LAN).
MAXCONN INFinite
MAXCONN maxconn
sets the maximum number of simultaneous adapter connections permitted at
any given time. When MAXCONN is specified as INFinite, there is no limit on
the number of connections. Any other value, maxconn, limits the number of
simultaneous connections to a decimal number in the range of 1–1024
(inclusive).
If MAXCONN is omitted, the default is MAXCONN INFinite.
RESTricted|UNRESTricted
sets the type of authorization required to connect to this LAN. Options are:
RESTricted
Defines a LAN with an access list to restrict connections. The LAN
owner will use the SET LAN command to GRANT or REVOKE access
to specific VM users (by userid). The COUPLE command will only allow
authorized users (those on the access list) to connect a simulated
adapter to a RESTRICTED network.
UNRESTricted
Defines a LAN with no access list. When CP is in control of the LAN,
connections to this LAN are not restricted by user ID. If an External
Security Manager (ESM) is in control of the LAN, the ESM may restrict
access.
When neither option is specified, the default is to define an UNRESTricted
LAN.
ACCOUNTing ON
ACCOUNTing OFF
Allows a Class B user to control whether accounting records are created for the
LAN being defined. The default setting may be changed by the VMLAN
statement in the system configuration file, and queried by QUERY VMLAN.
TYPE HIPERsockets
defines a VM LAN for use by simulated HiperSockets adapters. A HiperSockets
LAN can only accept connections from a simulated HiperSockets adapter.
If TYPE is omitted, the default is TYPE HIPERsockets.
MFS 16K
MFS 24K
MFS 40K
MFS 64K
sets the Maximum Frame Size (MFS) for adapters on this network. When an
adapter is connected to this LAN, it will adopt the network MFS. The MFS value
determines the amount of storage to be allocated for internal structures, and
limits the effective MTU size (Maximum Transmission Unit) for the coupled
adapters. For general internet communications, a lower MFS is probably better.
However, a high MFS may provide higher data transfer rates for applications
that are capable of using larger packet sizes.
If MFS is omitted, the default for HiperSockets is 16K. The MFS operand is not
valid for QDIO but the effective MFS is 8992 for a QDIO adapter.