Can I get a list of all computers on my network that respond to ARP? (or…?)

sofakng · Oct 26, 2007, 3:51 AM

I'm trying to find the IP address of an unused Linksys router. I know it's on my same subnet and is on the same block of IPs (eg. its 192.168.0.XXX).

Can I send a broadcast of ARP requests for every IP in my subnet to find the "active" IPs?

Cry Havok · Oct 26, 2007, 6:37 AM

Three options spring to mind:

Broadcast ping (not all devices will respond though)
Ping each IP one at a time
Do a factory-defaults reset to put it's IP back to the one specified in the manual

sofakng · Oct 26, 2007, 12:28 PM

How do I do a broadcast ping?

I'm trying to avoid resetting the router…

Cry Havok · Oct 26, 2007, 2:42 PM

It varies according to your OS. Check the help/man page for your version of ping and see if it's a command line switch or you simply ping the broadcast address.

cmb · Oct 27, 2007, 4:47 AM

I'd use nmap to ping scan the entire subnet. After that, even firewalled hosts that don't respond to the ping will be in your ARP table.

example:
nmap -sP 192.168.0.0/24