HP StorageWorks Enterprise File Services WAN Accelerator 3.0.4 deployment guide (AG421-96001, March 2007)

120 13 - TROUBLESHOOTING DEPLOYMENT PROBLEMS
Problem: Duplex Mismatch
This section describes common problems that can occur in networks in which duplex
settings do not match.
Duplex mismatch, which can cause performance degradation and lost packets, is a
condition that occurs when two devices that communicate over a network have
different duplex settings.
If all of your applications are slower after you have installed in-path HP EFS WAN
Accelerators, it might be due to network duplex mismatch.
To determine whether
the slowness is
caused by a duplex
mismatch
1. Create a pass-through rule for the application on the client-side HP EFS WAN
Accelerator and ensure that the rule is at the top of the in-path rules list.
You add a pass-through rule with the HP EFS WAN Accelerator command-line
interface (CLI) command in-path rule pass-through or via the Management
Console.
2. Restart the application.
3. Check that all connections related to the application are being passed-through.
If all connections related to the application are being passed-through and the
application’s performance does not return to original levels, the slowness is most
likely due to duplex mismatch.
The following sections describe several possible solutions to duplex mismatch:
 “Solution: Ensure Speed and Duplex Match” on page 120
 “Solution: Manually Set Speed and Duplex Settings” on page 120
 “Solution: Use an Intermediary Hub or Switch” on page 121
Solution:
Ensure Speed
and Duplex
Match
If a duplex mismatch is causing slow performance and lost packets after you deploy
HP EFS WAN Accelerators, first try ensuring that speed and duplex settings for each
in-path interface and corresponding peer interface in your network match. To view
interface speed and duplex settings, use the CLI command show configuration. By
default, the HP EFS WAN Accelerator auto-negotiates speed and duplex mode for all
data rates and supports full duplex mode and flow control. To change interface speed
and duplex settings, use the CLI command interface.
For more information, see the HP StorageWorks Enterprise File Services WAN
Accelerator Command-Line Interface Reference Manual.
Solution:
Manually Set
Speed and
Duplex Settings
If you have tried ensuring that speed and duplex settings match, as described in
“Solution: Ensure Speed and Duplex Match” on page 120, and duplex mismatch still
causes slow performance and lost packets, try manually setting (hard setting) speed
and duplex settings on one end of the interface and automatically setting (auto setting)
speed and duplex settings on the other end of the interface. HP recommends that you
try using half-duplex mode if full duplex mode does not work. To manually change
interface speed and duplex settings, use the CLI command interface.