lcp(8)lcp(8)Namelcp - Local Area Transport server (LAT) control program
/etc/lcp [ options ]
The LAT control program, provides the essential functions to control
and manage LAT terminal service. It allows you to start and stop LAT
service, modify and display configuration characteristics, and display
and set error counters to zero. The following command is usually
included in the file to automatically restart LAT service during
The following options can be set with
-s Starts LAT service. Enables connections from LAT termi‐
nal servers to host. If LAT parameters have not been
set, they take on default values specified in the
-r Resets LAT parameters to the following default values:
multicast timer: 30 seconds
node description: ``ULTRIX''
service description: ``ULTRIX LAT SERVICE''
-g Sets groups to grp1, grp2, ... , grpn. A number or
string of numbers can be used to set groups. The num‐
bers used for each group must be less than or equal to
255. For example:
A string of groups must be separated by commas with no
spaces. If the string exceeds the width of the screen
it must wrap over to the following line. You cannot use
a backslash (\) or a carriage return to break a string.
-h Sets a list of ttys (next argument) as being available
only for host-initiated connections. A string of ttys
must be separated by commas with no spaces. If the
string exceeds the width of the screen, it must wrap
over to the following line. You cannot use a backslash
(\) or a carriage return to break a string. Each tty
can optionally be associated with a specific port on a
specific terminal server by following the tty name by
the name of the server and port, separated by colons.
For example, the following command associates tty15 with
the port named "PORT7" on the terminal server named
/etc/lcp -h /dev/tty15:LAT_SERVER:PORT7
-H Sets a list of ttys (next argument) as being available
only for terminal server initiated connections. A
string of ttys must be separated by commas with no spa‐
ces. If the string exceeds the width of the screen it
must wrap over to the following line. You cannot use a
backslash (\) or a carriage return to break a string.
-m Sets multicast transmission timer to the specified time
(next argument). A node advertises its presence to the
LAT servers by sending out a multicast message over the
network. The time variable sets the interval between
transmissions. Valid intervals range from 10 to 255 sec‐
onds, with a default of 30 seconds.
-n Sets node to the specified name (next argument). Speci‐
fies the name that your node will be known by. Although
the Terminal Server keeps track of nodes without an
associated nodename, a LAT node must have a nodename in
order for a terminal user to establish a connection. A
node can have a list of associated services and service
ratings, specified by up to 16 alphanumeric characters.
Dollar ($) and underscore (_) characters are valid, but
leading underscores and trailing colons are removed. The
nodename must be unique on the Ethernet. The Terminal
Server displays the nodename as a service if you type
the command, and as a node if you type the command. The
nodename default is the hostname.
-N Sets node description to the specified message (next
argument). The node description allows for a short mes‐
sage to be displayed to LAT users, providing news or
additional node information. Specify up to 64 alphanu‐
meric characters. Dollar ($) and underscore (_) charac‐
ters are valid, but leading underscores and trailing
colons are removed. Leading ampersands (&) are not
allowed. The default is ``ULTRIX''. You must enclose
the string in double quotation marks (" ") if it con‐
tains one or more spaces.
-v A service node advertises one or more services. By
default the single service offered is the node name.
For example, node by default offers service The option
lets you change this default. It also lets you cause
the service node to advertise more than one service and
associate a given set of LAT ttys with each service by
appending a list of minor device numbers to the service
name. For example, the following command causes the node
to offer two additional services, "SERV1" and "SERV2":
/etc/lcp -v microv -v SERV1:/dev/tty15,/dev/tty16\
Devices tty15 and tty16 are used for SERV1. Devices
tty17, tty18, and tty19 are used for SERV2. All other
LAT ttys are used for the default service,
Note that normal LAT service is always associated with the first option
to appear. Therefore, if you wish to advertise additional services you
must define the service name for normal lat, even if you still want the
default service name, as in the above example.
Every time you issue a new lcp command with the option, the new set of
services that you define completely replaces any previously defined
services. To discontinue a previously defined service, reissue lcp
with the option without specifying that service. For example, to dis‐
continue the SERV1 service, use the following command:
/etc/lcp -v microv \
-V Sets service description to specified message (next argument).
It can be up to 64 characters in length. You must enclose the
string in double quotation marks (" ") if it contains one or
more spaces. If you are defining multiple services a given
description applies to the service name defined by the corre‐
sponding option (the first option corresponds to the first
option, and so on). For example, the following command asso‐
ciates the description "ULTRIX LAT service" with the service
name and description "service 1" with service name "SERV1".
/etc/lcp -v microv -v SERV1:dev/tty15,dev/tty16\
-V "ULTRIX LAT service" -V "service 1"
-t Stops LAT service. Disable connections from LAT terminal
servers to host.
-d Displays LAT characteristics. Shows the LAT parameters at their
current setting. The following is an example of the output of
% /etc/lcp -d
Node name: NODE Service name: NODE
Node Identification: ULTRIX LAT service
Service Identification: ULTRIX
Multicast timer: 30 seconds
LAT version: 5 eco: 0 LAT Protocol is active
-z Reinitializes (zeroes out) error counters. To test system per‐
formance over a period of time, zero the counters and observe
the information that accumulates.
-c Displays error counters in vertical format. If an interval
also is specified (next argument), displays error counters in
horizontal format every interval seconds. The following is an
example of the output of the option:
% /etc/lcp -c
67413 Frames received (rcv)
32 Duplicate frames received (rcvdup)
89005 Frames transmitted (xmit)
62 Retransmissions (rexmit)
0 Illegal messages received (illmesg)
0 Illegal slots received (illslots)
interval Continuously displays error counters in horizontal format,
waiting interval seconds between each iteration. Quit by send‐
ing a keyboard interrupt. The following is an example of the
output of the interval option:
% /etc/lcp 10
rcv rcvdup xmit rexmit illmesg illslots
67474 32 89066 62 0 0
67483 32 89067 62 0 0
67491 32 89073 62 0 0
67502 32 89089 62 0 0
-p Shows which LAT server/port combination a specific LAT tty
device is connected to. For example the following command dis‐
plays which terminal server and port are associated with tty15.
/etc/lcp -p /dev/tty15
The service and node names cannot be more than 16 characters long.
The user must have read and write access to a terminal.
The meaning of each error counter is explained below.
rcv Number of Ethernet LAT messages
rcvdup Number of duplicate messages received (normally indi‐
cates a system slowdown)
xmit Number of transmitted Ethernet LAT messages
rexmit Number of transmit frames that are sent more than once
illmesg Number of bad messages flagged by the LAT driver
illslots Number of bad transmission slots flagged by the driver
Messages indicating that user is not privileged or that LAT service is