You are not logged in.
- Topics: Active | Unanswered
#1 2011-02-28 13:44:24
- Cotton
- Member
- From: Cornwall, UK
- Registered: 2004-09-17
- Posts: 568
How can I identify the IP address of a device on my LAN?
If I attach a device to my LAN but have no idea of its IP address (ie it may not even be communicating), is it possible to identify its static address? Or will it only respond (to something like nmap) if the route of the transmitting device device is correct?
For instance, my PC is 192.168.0.4 and its default route is 192.168.0.1. If I attach another router that has an address of 192.168.1.254, how can I determine that its physically connected? Using nmap -PR 192.168.0.0/16 for host discovery doesn't reveal its there unless I change the default route to (something like) 192.168.1.1
Offline
#2 2011-02-28 14:34:44
- adee
- Member
- From: The Moon
- Registered: 2009-11-10
- Posts: 110
Re: How can I identify the IP address of a device on my LAN?
Ok, so:
PC1: 192.168.0.1
netw: 192.168.0.0/24
2nd router: 192.168.1.254
netw: 192.168.1.0/24
Those are not on the same subnet dude!
Offline
#3 2011-02-28 19:15:54
- Cotton
- Member
- From: Cornwall, UK
- Registered: 2004-09-17
- Posts: 568
Re: How can I identify the IP address of a device on my LAN?
Ok, so:
...Those are not on the same subnet dude!
I realise that, but they are sat at each end of a 1m ethernet cable and I want to know if its possible to recognise there is a device on the physical network even though its on a different subnet.
Offline
#4 2011-02-28 19:19:29
- Cotton
- Member
- From: Cornwall, UK
- Registered: 2004-09-17
- Posts: 568
Re: How can I identify the IP address of a device on my LAN?
It begs the question, what is the purpose of running "nmap 192.168.0.0/16 -PR" on one subnet if it can't see devices on the other.
Or am I missing something?
Offline
#5 2011-02-28 21:55:17
- fukawi2
- Ex-Administratorino
- From: .vic.au
- Registered: 2007-09-28
- Posts: 6,222
- Website
Re: How can I identify the IP address of a device on my LAN?
They can talk to each other up to Layer 2 (ie, the physical cable and MAC Addresses - you should be able to `arping` them) but they can't talk Layer 3 or above. This is the whole point of subnetting.
Are you familiar with our Forum Rules, and How To Ask Questions The Smart Way?
BlueHackers // fscanary // resticctl
Offline
#6 2011-02-28 21:56:27
- fukawi2
- Ex-Administratorino
- From: .vic.au
- Registered: 2007-09-28
- Posts: 6,222
- Website
Re: How can I identify the IP address of a device on my LAN?
It begs the question, what is the purpose of running "nmap 192.168.0.0/16 -PR"
If you:
1) Actually have a /16 subnet of address space in use; or
2) There is a /16 address space available via supernetting through a router.
Are you familiar with our Forum Rules, and How To Ask Questions The Smart Way?
BlueHackers // fscanary // resticctl
Offline