Service Manual

Enabling Flow-Based Monitoring
Flow-based monitoring is supported on the platform.
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 2
and Layer 3 ingress and egress traffic. You can specify traffic using standard or extended access-lists.
1. Enable flow-based monitoring for a monitoring session.
MONITOR SESSION mode
flow-based enable
2. Define access-list rules that include the keyword monitor. Dell Networking OS only considers port
monitoring traffic that matches rules with the keyword
monitor.
CONFIGURATION mode
ip access-list
For more information, see Access Control Lists (ACLs).
3. Apply the ACL to the monitored port.
INTERFACE mode
ip access-group access-list
Example of the flow-based enable Command
To view an access-list that you applied to an interface, use the show ip accounting access-list
command from EXEC Privilege mode.
Dell(conf)#monitor session 0
Dell(conf-mon-sess-0)#flow-based enable
Dell(conf)#
ip access-list ext testflow
Dell(config-ext-nacl)#seq 5 permit icmp any any count bytes monitor
Dell(config-ext-nacl)#seq 10 permit ip 102.1.1.0/24 any count bytes monitor
Dell(config-ext-nacl)#seq 15 deny udp any any count bytes
Dell(config-ext-nacl)#seq 20 deny tcp any any count bytes
Dell(config-ext-nacl)#exit
Dell(conf)#interface TenGigabitEthernet 1/1
Dell(conf-if-te-1/1)#
ip access-group testflow in
Dell(conf-if-te-1/1)#show config
!
interface TenGigabitEthernet 1/1
ip address 10.11.1.254/24
ip access-group testflow in
shutdown
Dell(conf-if-te-1/1)#exit
Dell(conf)#do show ip accounting access-list testflow
!
Extended Ingress IP access list testflow on TenGigabitEthernet 1/1
Total cam count 4
seq 5 permit icmp any any monitor count bytes (0 packets 0 bytes)
seq 10 permit ip 102.1.1.0/24 any monitor 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)
Dell(conf)#do show monitor session 0
ct-maa-s4820-2(conf-mon-sess-0)#do show monitor session 0
SessID Source Destination Dir Mode Source IP Dest IP
Access Control Lists (ACLs)
157