Users Guide
Figure 99. Port Monitoring Congurations on the S-Series
Dell Networking OS Behavior: All monitored frames are tagged if the congured 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 conguration 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 dierence 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 trac even after an MD participating in spanning tree 
protocol (STP) transitions from the forwarding to blocking.
Conguring Port Monitoring
To congure port monitoring, use the following commands.
1. Verify that the intended monitoring port has no conguration other than no shutdown, as shown in the following example.
EXEC Privilege mode
show interface
2. Create a monitoring session using the command monitor session from CONFIGURATION mode, as shown in the following 
example.
CONFIGURATION mode
monitor session
monitor session type rpm/erpm
type is an optional keyword, required only for rpm and erpm
3. Specify the source and destination port and direction of trac, as shown in the following example.
MONITOR SESSION mode
source
Example of Viewing Port Monitoring Conguration
To display information on currently congured port-monitoring sessions, use the show monitor session command from EXEC 
Privilege mode.
Dell(conf)#monitor session 0
Dell(conf-mon-sess-0)#$source ten 1/1 dest ten 1/2 dir rx
Dell(conf-mon-sess-0)#show c
!
monitor session 0
 source TenGigabitEthernet 1/1 destination TenGigabitEthernet 1/2 direction rx
Dell(conf-mon-sess-0)#
Dell(conf-mon-sess-0)#do show monitor session
 SessID Source Destination Dir Mode Source IP Dest IP
 ------ ------ ------------ --- ---- --------- --------
Port Monitoring
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