Port Monitoring
Diagnosing Switch Problems
page 32-24
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
Configuring Destination Switch
Follow the steps given below to configure the Destination Switch:
-> vlan 1000
-> spantree vlan 1000 admin-state disable
-> vlan 1000 members port 3/1-2 tagged
Enter the following QoS commands to override source learning:
-> policy condition c_ds1 source vlan 1000
-> mac-learning vlan 1000 disable
-> policy rule r_ds1 condition c_ds1 action a_ds1
-> qos apply
Port Monitoring
An essential tool of the network engineer is a network packet capture device. A packet capture device is
usually a PC-based computer, such as the Sniffer
®
, that provides a means for understanding and
measuring data traffic of a network. Understanding data flow in a VLAN-based switch presents unique
challenges, primarily because traffic moves inside the switch, especially on dedicated devices.
The port monitoring feature allows you to examine packets to and from a specific Ethernet port. Port
monitoring has the following features:
•
Software commands to enable and display captured port data.
•
Captures data in Network General
®
file format.
•
A file called
pmonitor.enc
is created in the
/flash
memory when you configure and enable a port
monitoring session.
•
Data packets time stamped.
•
One port monitored at a time.
•
RAM-based file system.
•
Statistics gathering and display.
The port monitoring feature also has the following restrictions:
•
All packets cannot be captured. (Estimated packet capture rate is around 500 packets/second.)
•
The maximum number of monitoring sessions is limited to one per chassis.
•
Only the first 64 bytes of the traffic is captured in ‘brief’ mode. If the monitoring capture-type is set to
‘full’ the entire packet is captured.
•
Link Aggregation ports can be monitored.
•
If both mirroring and monitoring are enabled, then packets is either mirrored
or
monitored (i.e., sent to
CPU), whichever comes first. See
“Mirroring on Multiple Ports” on page 32-16
for more information.
You can select to dump real-time packets to a file. Once a file is captured, you can FTP it to a Sniffer or
PC for viewing.