LINKLOOP(1M) LINKLOOP(1M)
NAME
linkloop - Link level loopback to verify LAN connectivity
SYNOPSIS
linkloop [ -n count ] [ -f devfile ] [ -t timeout ] [ -s
size ] [ -v ] linkaddr
HP-UX COMPATIBILITY
Level: HP-UX/NON-STANDARD
Origin: HP
DESCRIPTION
Linkloop uses IEEE 802.2 link level test frames to check
connectivity within a local area network (LAN). This
program differs from the remote loopback capability of
landiag(1) in that it only tests the link level
connectivity, and not that of the transport.
The required parameter is the link level address of a remote
node. Linkloop tests the connectivity of the local node and
the remote node specified by the link level address. The
link level address of a remote node can be found by
executing the landiag program on the remote node. In the
"Local LAN Interface Status" mode of landiag, execute the
display command to list the link address. This link level
address is usually represented as a hexadecimal string
prefixed with 0x (but can also be represented as a octal
string prefixed with 0 or as a decimal string). The address
must not be a multicast or broadcast address (the least
significant bit of the first byte of the link address must
be set to be zero).
The options are:
-n count Sets the number of frames to transmit. If
count is zero, linkloop transfers frames
indefinitely until an interrupt signal is
received (hit the break key). The default
value for count is one.
-t timeout Sets the amount of time (in seconds) to
wait for a reply from the remote node
before giving up. If timeout is zero,
linkloop waits indefinitely for a reply.
The default value for timeout is 2 seconds.
-s size Sets the size of the data to send. The
maximum data size is 1497, which is also
the default size.
-v Sets the verbose option. In addition to
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LINKLOOP(1M) LINKLOOP(1M)
the regular summary of test results, this
option causes the display of more extensive
error information. If there are header or
length errors, appropriate messages are
displayed. All verbose output is preceded
by the number of replies accepted before an
error occurred.
-f devfile Specifies which device file to use. The
device file must be an IEEE 802.3 device
file. If no device file is entered,
linkloop uses /dev/lan as the default. If
/dev/lan is not present or is the wrong
type of device file, then linkloop uses
/dev/ieee as the default.
The linkloop program can be aborted with the interrupt
signal. If aborted, the current results are printed.
Linkloop prints the result of the loopback test. If the test
fails, it prints a summary of the test and indicates the
type of error. The possible messages are:
address has bad format Link address entered on the
command line has bad format.
address is not individual Link address entered on the
command line does not have the
least significant bit of the first
byte set to 0.
frames sent Total number of frames sent.
frames received correctly Total number of frames received
without errors.
frames with length error Received frame length does not
match transmitted frame length.
If the verbose option is set, the
length received is printed.
frames with data error Received frame does not match
transmitted frame.
frames with header error Number of frames received
containing unexpected frame header
information. Either the source
address does not match the remote
address, the destination address
does not match the local address
or the control field is not the
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LINKLOOP(1M) LINKLOOP(1M)
TEST frame control field. These
frames are ignored. Linkloop
continues to try to receive the
reply frame until the read
operation times out.
reads that timed out Count of how many read operations
timed out before the reply was
received.
FILES
/dev/lan first default device file
/dev/ieee second default device file
SEE ALSO
landiag(1), lan(4).
HP Network Services/9000 LAN Node Manager's Guide.
DIAGNOSTICS
illegal count parameter Count is not a non-negative
integer or the number
specified is too large for the
local computer.
illegal timeout parameter Timeout is not a non-negative
integer or the number
specified multiplied by 1000
is too large for the local
computer.
illegal size parameter Size specified is not in the
range of 0..1497.
unable to use device file 1. Specified device file does
not exist or is of the wrong
type.
2. Linkloop is already being
executed by another user.
unable to use default device file
1. Default device file does
not exist or is of the wrong
type.
2. Linkloop is already being
executed by another user.
must be super user You must have super user
capabilities to execute the
linkloop program.
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