I need to scan a range of IPv6 addresses with Nmap, but I'm not sure how to do this. When scanning for an IPv4 range, I would usually do this:
nmap -sP 192.168.*.*
nmap -sP 192.168.1.*
but if I need to do this with an IPv6, how would I do it?
I would assume that the range you are trying to scan is
fe80:0000:0000:0000:0000:0000:0000:0000/112 which is the last 16 bits (the last section) of the address. That range includes 65,536 IPv6 addresses, probably all of which are going to time out when scanned. It will probably take most of a day (86,400 seconds - close enough to 65,536 at one second per timeout on average) just to ping that range to determine whether the machines are up or not.
But such small ranges are rarely seen. ISPs are often handing customers a /64 range each, (and it seems this is what you have) meaning that the customer has 18,446,744,073,709,551,616 individual IPv6 addresses. Scanning a single customer like this would take years.
There are discovery protocols that exist to allow you to find the exact IP address you need rather than scanning the entire range and these might be a better place to start.
There are some existing answers here that may still help: Which tool (apart from nmap) can I use to scan a range of IPv6 addresses?