I'd use wireshark. Has always worked. On Tue, May 5, 2009 at 2:49 PM, Roger E. Rustad, Jr <[email protected]>wrote:
> I've got a stupid tcpdump question, and I'm not sure what I'm missing > here. (tcpdump is what I'm using, but I'm thinking I need a different > tool or just learn how to use tcpdump correctly) > > My "requirement" is that I be able to plug in my laptop (Linux for this > example) and be able to instantly see what the IP address of a network > device (AP, switch, hub, router, etc) using just a cross over cable. > > Up to this point, I've been using tcpdump (e.g. with the flags -i arp) > and it's worked, but it's not working lately, and I suspect that it's > because some of the devices are on a different subnet entirely. > > e.g. > > tcpdump -i eth0 arp > > If I'm on the same subnet as the device, I'll get back tons of info, > including the right IP and MAC address. > > If, however, it's a weird different IP, I don't see that same info. > > In the field, I sometimes know the password of the wireless unit, but > the IP address is whacked (sometimes it's something stupid, like > 1.2.3.4). To make matters worse, the wireless units are meshed to other > units, so there are dependencies on this "working" system, and I can't > just reset them like I could if it was all from scratch. I have to > change the IP address of this unit eventually, as remotely managing a > bogus IP like 1.2.3.4 is a pain in the butt. > > So, here's my scenario: in the end of the day, I want to be able to get > in a cherry picker, plug in the bottom of a unit, and slam out one > command (or a set of commands) and instantly "see" the IP address of the > unit so that I can remote in locally and change it's IP. (No, there's > no console connection on this box, which is half my problem). > > (A little back history: these units come defaulted on a 10net network, > but then they, and then they're updated to the right 192 or 172 network > or whatever. However, admins often forget to write to memory after that > config change, and if I have to get in it afterwards, it's very > difficult without resetting the unit, as these units don't have console > ports and the only way to get the password back is to reinitialize the > unit with a dongle in the battery, thus nuking the whole config and > starting from scratch. Having this quick fix would be a godsend.) > > Thanks, guys. I'm all ears if you have a better way of possibly doing > this. > _______________________________________________ > LinuxUsers mailing list > [email protected] > http://socallinux.org/cgi-bin/mailman/listinfo/linuxusers >
