Viavi Apex Enterprise G3-APEX-ENT-32T, User Manual

Page: 355 / 380

Troubleshooting common issues
Chapter 16: Troubleshooting 355
is not listed, click Have Disk, then browse to the VMONI.SYS file located in the
Observer directory on your hard drive, select it, and click OK .
The VMONI Protocol Analyzer will now be available to install.
8. Restart the computer after you have completed installing the driver.
You should now be able to select an adapter when starting Observer.
Integrated adapters report all sent packets with bad TCP
checksum
Symptoms : All TCP packets sent from Observer or probe station across an
integrated network adapter contain bad TCP checksums.
Causes : Default driver settings for the card are incorrect. You must update the
driver and then disable the “Offload Transmit TCP Checksum” option.
Solutions
: Upgrade the driver for the integrated network adapter to the
Network Instruments/Intel Pro 1000 adapter driver. This driver is located in
the: \<Observer installation directory>\Drivers\IntelPro1000
directory.
1. After upgrading the driver, right-click the adapter and go to Control Panel >
Network Connections
>
Properties
.
2. On the General tab, click the Configure button.
3. Click the Advanced tab and find the Offload Transmit TCP Checksum option
and disable it.
4. Restart your system.
“No VLAN” shown while using a Gigabit NIC
Symptoms : “ No VLAN ” is displayed in VLAN Statistics and/or no 802.1Q tag
information is shown in your decode. The network adapter you use to capture
traffic is a Gigabit NIC.
Causes : Observer is not seeing the 802.1Q tag on packets being captured. This
is sometimes caused by your switch not sending tagged packets to Observer.
See VLAN Statistics tool is not working (page 356) for explanation/resolution
before proceeding.
Solutions : If you are using a Gigabit NIC to capture the traffic and you have
checked the switch configuration, then try using this solution. For BCM5751M
NetXtreme Gigabit chips found in IBM T43, HP laptops, and Dell Latitude laptops;
there is a registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet can
cause the driver and chip not to strip the 802.1Q headers. To set that key, you
must find the correct instance of the driver in Windows registry and change it.
1. Open the Windows registry editor. Start > Run > Command and type
regedit .
2. Search for “TxCoalescingTicks” and ensure this is the only instance that you
have.
3. Right-click the instance number (e.g., 0008) and add a new string value.
4. Type PreserveVlanInfoInRxPacket and give it the value 1 .
5. Restart the computer.