Network speed monitoring?

[jamesbird]

Trying to debug a wired network in a building. The wiring is all over the place and there are hidden and switches (and perhaps even hubs) I've yet to unearth.
I sit at 2 PCs and know their local links are running at 100meg, but how do I know what sort of links they go through to get to each other?
I'd like to be a bit more scientific that just seting a large file to move from one machine to another and working out the speed from that.
Any one know of a tool that'll crawl around the network and work out what I've got?

 

[frogtumor]

'Crawling' the network could be done with a utility called Net Scan Tools, or anything that can ping a range of addresses, but this is only useful for learning the addressing layout and how many active hosts there might be.

you cannot easily determine your physical layout with software, especially if your network is just a bunch of hubs or switches.
cable tracing sounds like the best approach here.

 

[bchizary]

sounds like a right pan of broth! i was in a place like that.... one day the network came down due to massive collisions, turned out there was a media convertor i knew nothing about that had given up the ghost.

Moral of the story- i would be tempted to crack on replacing the rickety old infrastructure with new stuff (even if its just lengths of cat5) which you do know about. It might not be cheap, but the event above brought us down long enough to justify it in that case, and the sooner you get started the quicker it will be done.

 

[flw]

One tool is a net work sniffer as mentioned above. But you have more than that and there is no single tool to discover all the devices and what they are.

I'd suggest you try the following as a start and modify as your local permissions/authority and skill allow, including the order of the steps.

1. Get a copy of your local DNS record and put in a csv or spreadsheet. Now you at least have all ip devices listed.

2. If you manage the clients AV from a server, you may have a handy list of ip's to machine name list. Now you have all the PC's. If you don't have something like this and your network discovery tool won't give it to you, you can just use cli and nbtstat -a all the ip's from your DNS list. You may already have the name to ip from your DNS service depending on what make (open source or windows or something else) of DNS you have.

3. A packet sniffer will show you any printers with a jetddirect interface as well as anyting that uses the network. You can also subtract the list of known AV PC machines from above as compared to what is listed when you browse your in network. This should show network printers, shared printers as well as other shared resources so those names with no ip's are most likely just shared printers/CD/Drives.

The sniffer will also show you any routers and inteligent switches that require ip's. If a ip repsonds to telnet, you have either a router or intelligent switch or some other networking device.

4. If you still cannot ID the ip device, then using the mac address from nbtstat you can look up the mfg and guess what it may be. If you have mostly HP printers this will get them as it will also get a router that won't respond to your telnet requests for whatever reason.

5. Of course the other tools at your fingers are tracert, ping (for response times once you know how many devices still between you and the target device)

So get to know your ip tools, get a packet sniffer, LAN Spy type app, MAC address list of mfg's, and your legs with flashlight to peek about. Track it starting with your DNS requestors list. Every local ip device will needs DNS so it will be on that list.

Remember that if a machine is off it will not repond to a ping or anything else. So a ping response only shows that the device is on and response times (if there is no firewall preventing it).