Concept Guide

If you congure the flow-based enable command and do not apply an ACL on the source port or the monitored port, both ow-based
monitoring and port mirroring do not function.
You cannot apply the same ACL to an interface or a monitoring session context simultaneously.
The port mirroring application maintains a database that contains all monitoring sessions (including port monitor sessions). It has
information regarding the sessions that are enabled for ow-based monitoring and those sessions that are not enabled for ow-based
monitoring. It downloads monitoring conguration to the ACL agent whenever the ACL agent is registered with the port mirroring
application or when ow-based monitoring is enabled.
The show monitor session session-id command displays the Type eld in the output, which indicates whether a particular
session is enabled for ow-monitoring.
Example Output of the show Command
DellEMC# show monitor session 1
SessID Source Destination Dir Mode Source IP Dest IP DSCP
TTL Drop Rate Gre-Protocol FcMonitor
------ ------ ----------- --- ---- --------- -------- ----
--- ---- ---- ----------- ---------
1 Te 1/2 remote-ip rx Port 0.0.0.0 0.0.0.0 0
0 No N/A N/A yes
DellEMC#
The show config command has been modied to display monitoring conguration in a particular session.
Example Output of the show Command
(conf-mon-sess-11)#show config
!
monitor session 11
flow-based enable
source TenGigabitEthernet 1/1 destination TenGigabitEthernet 1/1 direction both
The show ip accounting commands have been enhanced to display whether monitoring is enabled for trac that matches with the
rules of the specic ACL.
Example Output of the show Command
DellEMC# show ip accounting access-list
!
Extended Ingress IP access list kar on TenGigabitEthernet 1/1
Total cam count 1
seq 5 permit ip 192.168.20.0/24 173.168.20.0/24 monitor
DellEMC#show ipv6 accounting access-list
!
Ingress IPv6 access list kar on TenGigabitEthernet 1/1
Total cam count 1
seq 5 permit ipv6 22::/24 33::/24 monitor
Enabling Flow-Based Monitoring
Flow-based monitoring is supported on the platform.
Flow-based monitoring conserves bandwidth by monitoring only specied trac instead of all trac on the interface. This feature is
particularly useful when looking for malicious trac. It is available for Layer 2 and Layer 3 ingress trac. You can specify trac using
standard or extended access-lists.
1 Enable ow-based monitoring for a monitoring session.
MONITOR SESSION mode
142
Access Control Lists (ACLs)