I ran in to a strange issue w/ nmap.
a client is in an office space where they give the tenants a shared internet connection, each tenant has their own firewall to create their own protected lan.
they were running in to problems where they had an IP conflict on the WAN side.
so I used nmap to run a ping scan of that subnet which is a class C.
it came back saying all 254 hosts were alive.
so I worked with the network administrator that provides the shared connection indicating that he may need to change that subnet to something that supports more devices.
however they came back saying it definitely isn't an issue of too many devices on the subnet and that the ping tool may have given false results.
sure enough if I pinged some random IPs using the ping command that nmap says were alive I get no response.
has anyone seen nmap behave like this before?