Users Guide

Figure 100. Port Monitoring Configurations
Dell EMC 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 twe 1/1 destination twe 1/4 direction tx, if the MD port twe 1/9 is an untagged member of any VLAN,
all monitored frames that the MG port TeGig 1/6/2 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 EMC 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
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 traffic, as shown in the following example.
MONITOR SESSION mode
source
To display information on currently configured port-monitoring sessions, use the show monitor session command from
EXEC Privilege mode.
DellEMC(conf)#monitor session 0
DellEMC(conf-mon-sess-0)#$source twentyFiveGigE 1/1 dest twentyFiveGigE 1/2 dir rx
DellEMC(conf-mon-sess-0)#show c
!
monitor session 0
source twentyFiveGigE 1/1 destination twentyFiveGigE 1/2 direction rx
DellEMC(conf-mon-sess-0)#
DellEMC(conf-mon-sess-0)#do show monitor session
SessID Source Destination Dir Mode Source IP Dest IP DSCP TTL Drop
Rate Gre-Protocol FcMonitor
------ ------ ------------ --- ---- --------- -------- ---- --- ----
---- ----------- ---------
0 Tf 1/1 Tf 1/2 rx Port 0.0.0.0 0.0.0.0 0 0 No
N/A N/A No
650
Port Monitoring