Deployment Guide

Enabling Flow-Based Monitoring
Flow-based monitoring conserves bandwidth by monitoring only specified traffic instead of all traffic on the interface. This
feature is particularly useful when looking for malicious traffic. It is available for Layer 3 ingress traffic. You can specify traffic
using standard or extended access-lists.
NOTE: Flow-based monitoring is supported for known unicast egress traffic.
1. Create a monitoring session.
CONFIGURATION mode
monitor session session-id
2. Enable flow-based monitoring for a monitoring session.
MONITOR SESSION mode
flow-based enable
3. Specify the source and destination port and direction of traffic.
MONITOR SESSION mode
source source—port destination destination-port direction rx
4. Define IP access-list rules that include the monitor keyword. For port monitoring, Dell EMC Networking OS only considers
traffic matching rules with the monitor keyword.
CONFIGURATION mode
ip access-list
To define access lists, see the Access Control Lists (ACLs) chapter.
5. Allocate a CAM region so that you can apply the ACL you created to the monitoring session.
CONFIGURATION mode
cam-acl l2acl number ipv4acl number ipv6acl number ipv4qos number l2qos number l2pt
number ipmacacl number vman-qos number ipv4mirracl number
6. Apply the ACL to the monitored port.
MONITOR SESSION mode
ip access-group access-list-name
To view an access-list that you applied to an interface, use the show ip accounting access-list command from EXEC
Privilege mode.
DellEMC(conf)#monitor session 0
DellEMC(conf-mon-sess-0)#flow-based enable
DellEMC(conf)#ip access-list ext testflow
DellEMC(config-ext-nacl)#seq 5 permit icmp any any count bytes monitor
DellEMC(config-ext-nacl)#seq 10 permit ip 102.1.1.0/24 any count bytes monitor
DellEMC(config-ext-nacl)#seq 15 deny udp any any count bytes
DellEMC(config-ext-nacl)#seq 20 deny tcp any any count bytes
DellEMC(config-ext-nacl)#exit
DellEMC(conf)#interface tengigabitethernet 1/1/1
DellEMC(conf-if-te-1/1/1)#ip access-group testflow in
DellEMC(conf-if-te-1/1/1)#show config
!
interface TenGigabitEthernet 1/1/1
ip address 10.11.1.254/24
ip access-group testflow in
shutdown
DellEMC(conf-if-te-1/1/1)#exit
DellEMC(conf)#do show ip accounting access-list testflow
!
Extended Ingress IP access list testflow on TenGigabitEthernet 1/1/1
Total cam count 4
seq 5 permit icmp any any 40 monitor 40 count bytes (0 packets 0 bytes)
seq 10 permit ip 102.1.1.0/24 any monitor 40 count bytes (0 packets 0 bytes)
seq 15 deny udp any any count bytes (0 packets 0 bytes)
seq 20 deny tcp any any count bytes (0 packets 0 bytes)
DellEMC(conf)#do show monitor session 0
SessionID Source Destination Direction Mode Source IP Dest IP DSCP TTL
Drop Rate Gre-Protocol FcMonitor
662
Port Monitoring