I have 5 Cisco switches (two SG500, two SG220, and one 2960 where the other switches are connected) used for camera surveillance connected to each other using optical fibre. I need to monitor the traffic generated between the switches. As I am not allowed to install any software on my NVR, I need to know the console commands, or if I can monitor it from another PC with any auxiliary software. Any suggestions?

  • 3
    Most people do this wtih MRTG (etc.) via SNMP.
    – Ricky
    Jun 23, 2015 at 21:18
  • the switch is not generating the CCTV traffic, the DSP/video encoder is. Sep 16, 2016 at 19:30
  • 1
    show interface tells you traffic load Sep 16, 2016 at 19:31
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 11, 2017 at 17:36

3 Answers 3


Option 1. One way is to simply use a bandwidth calculator for the cameras in use and quantity of streams. Most 720P (1.3 mega pixels) at 7 fps (frames per second) only use about 2mb/s.

Option 2. To actually monitor the switches one method is to enable SNMP and monitor the interfaces. I use PRTG but there are others. I'm not recommending it specifically. You could choose others. I'm just familiar with this. They have 100 sensors for free. Each monitor point for example a switch port, cpu, ram, fans, is considered a sensor in PRTG. The setup wizard will even scan and auto add sensors. You may need to delete some to get it under 100 at that time if you use the auto scan network feature. If your only interested in one switches interfaces just manually add that switch and do an auto scan on it.

To enable the basic SNMP required in the Cisco switches or even routers use the commands below (below the descriptions)

Line 3 enables a read only (ro) community with your choice of name. Most use the name public. Line 4 creates a read write (rw) community name. This isn't needed for most snmp to simply read information. Line 5 is the access control list that identifies the ip address that allowed to use the snmp. Notice the number 100 on lines 3 and 4. That's the ACL number in line 5. The ip address in the ACL should be the SNMP server like PRTG as an example. You can add more to the list of required.

configure terminal
snmp-server community myCommunityNameGoesHere ro 100
snmp-server community myCommunityNameGoesHere rw 100
access-list 100 permit
copy run start (saves to nvram) 

Option 3. If you just need raw numbers you can do show interface g1/0/52 for example and get some numbers.

Option 4. If you can get a copy of Cisco Network Assistant (CNA) (deprecated) or other Cisco monitoring software that could be an option. They can also graph bandwidth while your on the software but no history like PRTG.


It appears from your question that the 2960 is the "core" or central switch. The most straightforward answer is to create a SPAN port on the central 2960 and feed it into your other PC. Then you can use a tool like Wireshark to look at the data.

! Monitor source is all the ports connected to your other switches
monitor session 1 source interface Gi0/1, Gi0/2, Gi0/3, Gi0/4
! Monitor destination is your PC that's capturing the data
monitor session 1 destination interface Gi0/24
  • 1
    The OP could do some homework and investigate using snmp with software such as mrtg, what'sUp gold, nagios, icinga, opennms, etc...
    – user4565
    Jun 23, 2015 at 20:36
  • Don't forget Cacti.
    – squirrely
    Mar 20, 2016 at 9:31

You can enable snmp on the switch you want to monitor and use a grapher like PRTG or Cacti to look at your traffic.

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