Any good network monitoring tools that are free?

[dubsdj]

Hi I'm having some issues with network performance and was wondering if anybody knows of good FREE tools that are easy to use that might help me identify issues on my network?

I have tried various tools but can't seem to make much sense of them.

[Tripredacus]

I have used WireShark and Microsoft Network Monitor

[VideoRipper]

that are easy to use [...] help me identify issues on my network?

You know these two contradict each other?

I have tried various tools but can't seem to make much sense of them

As with a lot of these kinds of things, there are no one-click-solves-all solutions

(see my first statement above)

[CoffeeFiend]

Wireshark is great but you do have to know what you're looking at and networking in general. There's simply no way around that.

[nitroshift]

I second Wireshark, but as Coffee said, you MUST have some network-related knowledge.

[dubsdj]

That Wireshark looks good.

Can I connect to Switches SNMP with it?

Does wireshark only look at packets that are going to and from the PC that its installed on?

Im not a Network King but I do have a bit of know how with networking so hopefully I can find my way around Wireshark..

Edited May 27, 2010 by dubsdj

[CoffeeFiend]

Can I connect to Switches SNMP with it?

That's not its purpose. There's other tools for that (cacti, munin, nagios, etc)

Does wireshark only look at packets that are going to and from the PC that its installed on?

Nothing can by itself look beyond that. If you want to peek at traffic from elsewhere then you can use a span port on fancy cisco switches or similar. Or you can take your laptop there, preferably with a network tap

[VideoRipper]

Nothing can by itself look beyond that.

Granted, it has been around 15 years ago I did this, but you can monitor traffic

from/to other computers by using an old Hub

The only real problem is that your maximum network throughput will be limited

to 10Mbit, but it is cheap if you can get a hold on such an ancient device.

FYI: An Ethernet network hub is an old type of "Switch", with no intelligence at

all built-in like present day switches have.

Because there's no intelligence in them, all data is present on all ports and

connected devices (computers, N/W-printers, etc.) had to filter out their own

packets from the network.

So when you connect your PC to a hub you can listen in on all traffic

[CoffeeFiend]

Granted, it has been around 15 years ago I did this, but you can monitor traffic

from/to other computers by using an old Hub

That's another way, if you can find one. Most things labeled and sold as "hub" nowadays are actually switches so useless for this. Using a hub is very often not an option either: unplugging a server from its gigabit switch to plug it in a 10mbit half duplex device will do funny things to performance (ditto if you stick the hub between 2 gigabit switches). One basically has to look on the used market for some old device (or build your own) -- or again, getting a network tap which is admittedly more expensive but doesn't suck. And that still doesn't make the PC see beyond itself (traffic that doesn't get to its NIC), it merely makes traffic go everywhere

[cluberti]

If you're monitoring anything more than one or two devices, getting a switch with an admin port is a must. To the OP, if you want to MONITOR your network (rather than troubleshoot it or watch every packet), consider any of the packages previously mentioned, but add another: OpManager. If you manage 10 devices or less, it's free.

[dubsdj]

If you're monitoring anything more than one or two devices, getting a switch with an admin port is a must. To the OP, if you want to MONITOR your network (rather than troubleshoot it or watch every packet), consider any of the packages previously mentioned, but add another: OpManager. If you manage 10 devices or less, it's free.

Thanks Everyone, I've got some good info to work with