Home LAN traffic monitoring tool

[nalooti]

Hi all,

It's been a while I wasn't here but let me first say that I really appreciate this site, its reviews, forum and great articles. Actually, before I buy anything PC/network-related, I take a look here for advices.

Here I am to ask advices on free network traffic monitoring tools. After googling a while I saw dozens of free network monitoring tools but they are mostly too heavy for my simple needs. What I want is just a tool letting me view traffic between every nodes (not just bandwidth usage of my ISP), that is a tool able to see all active IP addresses on my LAN and telling me the bandwidth used instantly between two any given nodes. Of course, it'd be useful to also see what kind of traffic (TCP, HTTP, etc.) is getting what bandwidth but it is a plus. What I'm interested in is just the amount of bandwidth used between nodes.

Some criteria:
- No SNMP: because simply my devices don't support it
- No any other active monitoring: I just don't want to add traffic for monitoring needs, nor use additional CPUs on my nodes to do it

This leaves me with passive monitoring tools able to see the traffic and present it with diagrams. Of course, the free soft I'm looking for will be installed on a PC (laptop) that I will connect to a switch port, mirroring another port where all traffics are passed through. So all the tool has to do is to put my PC on promiscuous mode (to see all frames) and then graphically represent the traffic between each two nodes that I'll chose.
I must mention that I'm not interested in packet/protocol sniffers giving details on every bit within frames like Wireshark. I just want bandwidth usage graphically. Also, tools giving bandwidth on a given interface will not do because I want to see also the traffic between other nodes and not only on my PC's NIC interfaces.

I found "bandwidthd" interesting and simple enough, but wasn't able to make it work in Windows (it is originally written for Linux).

Thanks in advance for your advices and telling me what do you use and how.
nalooti

 

[stevech]

With switched Ethernet, this can be done but not simply.
Example: WiFi router. Several PCs on the wired LAN ports.

Intra-LAN traffic (PC to PC, PC to NAS, etc.) cannot be monitored as above, as the traffic appears only on the two involved ports.
One way is to buy/use a "lightly managed ethernet switch". I have one, aa Netgear GS108e. (probably discontinued, but low cost on eBay). Connect it to the WiFi router LAN port. Move all other LAN port cables on the WiFi router to the Ethernet switch.

Use the Ethernet switch admin software (fee download) to config. one port on the switch to be a mirror port so that it can monitor all the other ports on the switch. On that one mirrored port, you'd use a PC running something like Ethereal or one of the many.

But if you want to only monitor PCs/WiFi devices traffic to/from the Internet, it's simpler. Some routers, or routers with 3rd party firmware, will monitor that one WAN port (to the internet modem) and keep stats.

 

[nalooti]

With switched Ethernet, this can be done but not simply.
Example: WiFi router. Several PCs on the wired LAN ports.

Intra-LAN traffic (PC to PC, PC to NAS, etc.) cannot be monitored as above, as the traffic appears only on the two involved ports.
One way is to buy/use a "lightly managed ethernet switch". I have one, aa Netgear GS108e. (probably discontinued, but low cost on eBay). Connect it to the WiFi router LAN port. Move all other LAN port cables on the WiFi router to the Ethernet switch.

Use the Ethernet switch admin software (fee download) to config. one port on the switch to be a mirror port so that it can monitor all the other ports on the switch. On that one mirrored port, you'd use a PC running something like Ethereal or one of the many.

But if you want to only monitor PCs/WiFi devices traffic to/from the Internet, it's simpler. Some routers, or routers with 3rd party firmware, will monitor that one WAN port (to the internet modem) and keep stats.

OK, thanks,
I should have mentioned that my switches are GS108E and that I already wanted to configure port mirroring as you described.
My problem is not how to do it physically; I know how to do it but I just want a piece of free soft analyzing all the frames passing through that mirrored port in order to find the bandwidth used between each two nodes (IPs) and present the result in graphs.

As you may know the GS108E 's ProSafe utility give ports stats only numerically as the total of all traffic (between all nodes)

Take a look at bandwidthd :
http://bandwidthd.sourceforge.net/

I want something similar since I couldn't get it to work on Windows