[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]
Hi Gordon, just a quick question, I have a cisco sip phone, and would like to connect it to a sip server for call in and out access any ideas? Thanks ed On 16/05/2010 12:13, "Gordon Henderson" <gordon+dcglug@xxxxxxxxxx> wrote: > On Fri, 14 May 2010, Rob Beard wrote: > >> Hi folks, >> >> I'm in the process of trying to create a network diagram for a network which >> looks like a tin of spaghetti. Now some of the switches connected to this >> network are managed and give me some details about the network (although not >> much that I can decipher). I believe there are a couple of 10MBit hubs on >> this network too which I'm guessing is causing a bit of a bottleneck. >> >> So I was wondering, does anyone know of any tools which might be able to work >> out what is on the network (I'm thinking maybe by device Mac address) so I >> can try and pinpoint what is on the network? > > It's hard when you've come into something that's grown "organically" over > the years and my own experiences of doing this involve getting down on > your hands and knees with big sheets of paper to draw on, and pags of > sticky labels to label devices and cabled, and manually mapping it out the > hard way - for the physical side of it, anyway. > > And sometimes it's easier to just rip it out and start again. Especially > when in one case I did a while back you lift a floor plate and find a mass > of charred cables... > > As for identifying devices - you might want to use tools like ping, > arping, fping and nmap - or simply even pinging the broadcast addresses > then looking at the arp-cache (from a linux box, although no-doubt there > are equivalent tools in the windows world!) Won't find boxes that are > turned off though... However with a list of MAC addresses, you can then > look them up to find the manufacturers - sometimes handy if you find an > Acer laptop hidden away on a network when they tell you they've never > bought any Acers... > > You may be able to snoop for switch spanning tree information - which > might help, but it's not an area I've spent much time on - and if you have > passive hubs, or cheap switches it's really not going to help. > > Another method is to simply unplug everything and wait to see who shouts > ;-) Potentially career limiting though!!! > >> What I'd ideally like to achieve is to find out what is on the other end of >> the network port but these switches (Linksys SRW224G4) don't seem to let me >> do that. > > What you can do here is get a Linux box with 2 Ethernet ports and plumb it > in-line with the switch port and the lead coming out of it. (watch out for > the need for cross-over cables) You'd need to configure the Linux box as > an Ethernet switch first (bridge-tools) then you can snoop the traffic > going over that port and built up a list of MAC addresses of devices > connected to that port. It's invasive though in that there will be a short > period of down-time when you physically unplug the connections and re-wire > then through the Linux box. > > However that's a nice switch and it is "managable" in that it support snmp > monitoring and it supports port mirroring, so if there is a spare port, > you can configure it to mirror another port, then all traffic going down > the mirrored port will come down the spare port too (You just need to make > sure it doesn't come back!) - so you stick a Linux box in it, run > tcpdump/tshark, iftop, etc. and otherwise snoop the traffic and/or the arp > cache. > > Good luck :) > > Gordon -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html