FTOS Configuration Guide for the C-Series - Force10 Networks

FTOS Behavior: On the C-Series and S-Series, all monitored frames are tagged if the configured
monitoring direction is transmit (TX), regardless of whether the monitored port (MD) is a Layer 2 or
Layer 3 port. If the MD port is a Layer 2 port, the frames are tagged with the VLAN ID of the VLAN to
which the MD belongs. If the MD port is a Layer 3 port, the frames are tagged with VLAN ID 4095. If
the MD port is in a Layer 3 VLAN, the frames are tagged with the respective Layer 3 VLAN ID. For
example, in the configuration source gig 6/0 destination gig 6/1 direction tx, if the MD port
gigabitethernet 6/0 is an untagged member of any VLAN, all monitored frames that the MG port
gigabitethernet 6/1 receives are tagged with the VLAN ID of the MD port. Similarly, if BPDUs are
transmitted, the MG port receives them tagged with the VLAN ID 4095. This behavior might result in a
difference between the number of egress packets on the MD port and monitored packets on the MG
port.
Important Points to Remember
• Port Monitoring is not supported on EtherScale platforms.
• Port Monitoring is supported on physical ports only; VLAN and port-channel interfaces do not support
port monitoring. A SONET port may only be a monitored port.
• The Monitored (source, “MD”) and Monitoring ports (destination, “MG”) must be on the same switch.
• In general, a monitoring port should have “no ip address" and "no shutdown" as the only configuration;
FTOS permits a limited set of commands for monitoring ports; display them using the command ?. A
monitoring port also may not be a member of a VLAN.
Configuring Port Monitoring
To configure port monitoring:
Step Task Command Syntax Command Mode
3 Verify that the intended monitoring port has no
configuration other than no shutdown, as shown in
Figure 88.
4 Create a monitoring session using the command
monitor session from CONFIGURATION mode, as
shown in Figure 88.
5 Specify the source and destination port and direction
of traffic, as shown in Figure 88.
show interface EXEC Privilege
monitor session CONFIGURATION
source MONITOR SESSION
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