Users Guide

Figure 115. Port Monitoring Congurations
Dell Networking OS Behavior: All monitored frames are tagged if the congured monitoring direction is egress (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 conguration source PeGi 255/0/0 destination
TenGigabitEthernet 0/23 direction tx, if the MD port PeGi 255/0/0 is an untagged member of any VLAN, all monitored frames that
the MG port PeGi 255/0/0 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 dierence between the number of egress packets on the MD
port and monitored packets on the MG port.
Dell Networking OS Behavior: The platform continues to mirror outgoing trac even after an MD participating in spanning tree protocol
(STP) transitions from the forwarding to blocking.
Important Points to Remember
• The destination interface should have no congurations except shutdown and no shutdown. By default, the "no ip address" must be
present. A MG/ destination port cannot be a member of a VLAN.
• The range command is supported in the source command to specify multiple source ports.
• You can enter multiple source statements in a monitoring session. A source port can be monitored by more than one destination port.
• A destination port can be a physical or port-channel interface, and can be used in multiple sessions. A PE port or a VP lag cannot be
congured as a destination port.
• A maximum of 4 destination ports are supported per port pipe. For information about port pipes on the switch, see Port-pipes.
• Flow-based monitoring is supported on all types of source interfaces.
Examples of Port Monitoring
In the following examples of port monitoring, the four source ports 0/13, 0/14, 0/15, and 0/16 belong to the same port pipe and mirror
trac to four dierent destinations (0/1, 0/2, 0/3, and 0/37).
You cannot add another destination on the same port pipe in a monitoring session because a maximum number of four destination ports are
supported on the same port pipe. If you congure another destination port on the same port pipe, a Syslog message is generated: Unable
to create MTP entry for MD interface MG interface in stack-unit stack-num port-pipe port-num.
Example of Changing the Destination Port in a Monitoring Session
Dell(conf)#mon ses 300
Dell(conf-mon-sess-300)#source tengig 0/17 destination tengig 0/4 direction tx
%Unable to create MTP entry for MD tenG 0/17 MG tenG 0/4 in stack-unit 0 port-pipe 0.
Dell(conf-mon-sess-300)#
Dell(conf-mon-sess-300)#source tengig 0/17 destination tengig 0/1 direction tx
Dell(conf-mon-sess-300)#do show mon session
SessionID Source Destination Direction Mode Type
--------- ------ ----------- --------- ---- ----
0 Te 0/13 Te 0/1 rx interface Port-based
Port Monitoring
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