llc2_loop(1M) System Administration Commands llc2_loop(1M)NAMEllc2_loop - loopback diagnostics to test the driver, adapter and net‐
work.
SYNOPSIS
/usr/lib/llc2/llc2_loop2 [-v] ppa
/usr/lib/llc2/llc2_loop3 ppa sap frames
/usr/lib/llc2/llc2_loop3 ppa type frames
/usr/lib/llc2/llc2_loop4 [-v] ppa
DESCRIPTION
Loop 2
The loop2 test sends a NULL XID frame to the broadcast (all 1's) desti‐
nation MAC address. The source SAP (Service Access Point) value used is
0x04 (SNA's SAP). Therefore, if SNA is running on the system, the
loop2 test will fail. The destination SAP value is the NULL SAP
(0x00). This test finds out who is listening and can receive frames
sent out from a node. The verbose (-v) option displays the MAC address
of responding nodes. All possible responders may not be displayed,
since the loop2 test only waits for responses for 2 seconds, but during
this time 50-200 nodes may be displayed. The most likely error is:
Unexpected DLPI primitive x, expected y.
where x = 5 and y = 6. From /usr/include/sys/dlpi.h, the expected
return value from one of the DLPI primitives is 6 (DL_OK_ACK), but
instead a 5 (DL_ERROR_ACK) was received. This can occur for two rea‐
sons:
· The loop2 command was issued to a non-existent PPA (Physical Point
of Attachment).
· The SAP (0x04) is already in use (for example, the SNA subsystem
is up).
Loop 3
The loop3 test sends 1,495 byte Unnumbered Information (UI) frames to
the NULL (all 0's) destination MAC address. This should be used along
with data capture either on the local node or another node on the same
LAN to verify the transmission of data. The ppa argument specifies the
adapter on which to run the test. The ppa is the relative physical
position of the adapter and may be ascertained by viewing the adapter
configuration (see llc2_config(1)). For Token Ring or Ethernet, spec‐
ify an even sap value from 2 through 254, or, for Ethernet only, any
type value from 1519 (0x05ef) through 65535 (0xffff). It is advised to
pick a value that is easily recognized when the data capture output is
viewed.
frames is the decimal number of 1,495 bytes packets to transmit. The
test will only display a message if a failure occurs.
Loop 4
The loop4 test sends a TEST frame (no information field) to the broad‐
cast (all 1's) destination MAC address. The source SAP value used is
0x04 (SNA's SAP). Therefore, if SNA is running on the system, the
loop4 test will fail. The destination SAP value is the NULL SAP (0x00).
This test finds out who is listening and can receive frames sent out
from a node. The verbose (-v) option displays the MAC address of
responding nodes. All possible responders may not be displayed since
the loop4 test only waits for responses for 2 seconds, but during this
time 50-200 nodes may be displayed. The loop4 test displays informa‐
tion similar to the following example if other nodes are listening and
respond (verbose mode):
-Attaching
-Binding
-Sending TEST
-Responders
1-0000c0c12449
2-08000e142990
3-08000e142a51
4-0000c0450044
5-0000c0199e46
-Unbinding
-Detaching
5 nodes responding
The errors displayed are the same as for loop2.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWllc │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOllc2_config(1), llc2(4), attributes(5), llc2(7D)NOTES
For information about how to start the service, see llc2(7D)SunOS 5.10 18 May 1999 llc2_loop(1M)
