Expand Configuration and Management Manual (H06.21+, J06.10+)

Troubleshooting
Expand Configuration and Management Manual — 529522-013
20 - 12
Expand Line-Handler Process Problems
Expand Line-Handler Process Problems
Table 20-7 lists procedures to help you resolve Layer 4 and Layer 2 Expand line-
handler process problems.
INFO PROCESS $NCP, SYSTEMS Displays all known systems. If no connection is
established, the SYSTEMS option displays an infinite
time factor and hop count. The SYSTEMS option is
similar to the CONNECTS option, except that the
CONNECTS option displays only the systems
connected.
INFO PROCESS $NCP,
SUPERP
ATH
Displays the effective time factor (ETF), time factor
(TF), logical device (LDEV) number, and local and
remote processors for each path within each multi-
CPU path on the selected system.
PROBE PROCESS $NCP Provides status information about the intermediate
nod
es in a path and displays the typical time to each
destination node.
Note. You should be familiar with the Expand End-to-End protocol before attempting to
an
alyze Layer 4 and Layer 2 problems. The End-to-End protocol is described in
Path Function
of the Expand Subsystem on page 17-13.
Table 20-7. Expand Line-Handler Process Problem-Resolution
Procedures
(page 1 of 2)
Problem Procedure
Expand Layer 4
(End-t
o-End)
protocol
The End-to-End protocol accepts packets for the line(s) from the local
node and passthrough packets destined for other nodes. The End-to-
End protocol also selects the line or manages the interface for the
X25AM subsystem, the SNAX/APN subsystem, the NonStop TCP/IP
subsystem, the Asynchronous Transfer Mode (ATM) subsystem, the
SWAN concentrator, or the ServerNet/FX adapter subsystem.
You can use the Expand subsystem SCF STATS PATH command to
obt
ain a detailed listing of the Layer 4 statistics.
Layer 4 statistics indicate Layer 4 checksum errors, buffer pool failures,
and ou
t-of-sequence (OOS) errors. These errors can point to these
problems:
•
Inadequate buffer pool allocation
•
Excessive traffic causing activation of Layer 4 flow control
•
A high number of packets arriving on different lines out of sequence,
contributing to processing overhead
Table 20-6. Identifying $NCP Problems With SCF Commands
Command Use