[Last Call] Learn about multicloud storage options and how to improve your company's cloud strategy. Register Now


network monitoring..

Posted on 2004-10-21
Medium Priority
Last Modified: 2016-10-28
Here is a senario, would I still be able to effectively monitor the network traffic?

I have two managed HP switches stacked together with most of the clients and servers on it, I have another unmanaged HP switch with some clients on it, that unmanaged switch is connected to the managed stack with a cat5 cable. I would imagine this would work fine since the traffic from the unmanaged switch would flow through the managed stack, and into the monitor port that the sniffer is connected to.

Thanks in advance!
Question by:cbtech
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions

Accepted Solution

syn_ack_fin earned 500 total points
ID: 12372742

The monitor port is set to span other specific ports. If the unmanged switch connects to port 2 and you have port 1 set to monitor port 2 then you will see any traffic coming across port 2 to your switch on port 1. If the two systems that are talking to each other, however, are on the same unmanged switch, you will never see the traffic.

In the below example, if you have the correct port monitored on switch two, you will see traffic from PC1 and PC2 going to PC3 but you would not see traffic from PC1 going to PC2.

PC 1          PC 2                             PC3
|               |                                  |
SWITCH ONE ------------------SWITCH TWO


Author Comment

ID: 12372799
So in my case, since I have the two managed switches stacked, making them virtually one, any traffic between the two managed stacked switches and the unmanaged one I could see, but any traffic local to the unmanaged switch I cannot see, since it doesnt come across from the unmaged switch to the managed stack?


Expert Comment

ID: 12385484
syn_ack_fin is correct.

You won't see any traffic that stays on the unmanaged switched and never comes over into the manages switches.

Expert Comment

ID: 12396798
We use Paessler Router Traffic grapher - http://www.paessler.com/prtg

You can set it up to monitor any port on the managed switches if you enable SNMP.  Gives you nice graphs of traffic going in and out of any port in real time.  But like the other guys said, any traffic staying within the unmanaged switch can't be monitored.

Try out the program - the free edition allows you to setup one monitor - so you can try monitoring one port and get an idea of the traffice.  The full version is pretty cheap - $49 I think.  Runs a service on any windows computer.  I highly recommend it.
Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

WARNING:   If you follow the instructions here, you will wipe out your VTP and VLAN configurations.  Make sure you have backed up your switch!!! I recently had some issues with a few low-end Cisco routers (RV325) and I opened a case with Cisco TA…
This article will show how Aten was able to supply easy management and control for Artear's video walls and wide range display configurations of their newsroom.
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…

656 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question