Configuring Port Monitoring - Dell S4820T Configuration Manual

Example of Viewing a Monitoring Session
In the example below, 0/25 and 0/26 belong to Port-pipe 1. This port-pipe has the same restriction of
only four destination ports, new or used.
Dell(conf-mon-sess-300)#do show mon session
SessionID Source
--------- ------
0 Te 1/13 Te 1/1
10 Te 1/14 Te 1/2
20 Te 1/15 Te 1/3
30 Te 1/16 Te 1/37
100 Te 1/25 Te 1/38
110 Te 1/26 Te 1/39
300 Te 1/17 Te 1/1
Dell(conf-mon-sess-300)#
Given these parameters, the following illustration shows the possible port monitoring configurations on
the S-Series.
Figure 99. Port Monitoring Configurations on the S-Series
Dell Networking OS Behavior: All monitored frames are tagged if the configured 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 configuration source TeGig
6/1 destination TeGig 6/2 direction tx, if the MD port TenGig 6/1 is an untagged member of any VLAN, all
monitored frames that the MG port TeGig 6/2 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.
Dell Networking OS Behavior: The platform continues to mirror outgoing traffic even after an MD
participating in spanning tree protocol (STP) transitions from the forwarding to blocking.

Configuring Port Monitoring

To configure port monitoring, use the following commands.
1. Verify that the intended monitoring port has no configuration other than no shutdown, as shown in
the following example.
EXEC Privilege mode
754
Destination Direction Mode
----------- --------- ----
rx
rx
rx
rx
tx
tx
tx
Type
----
interface Port-based
interface Port-based
interface Port-based
interface Port-based
interface Port-based
interface Port-based
interface Port-based
Port Monitoring