Question

I’m making a network monitoring program with PHP.
I want to be able to connect to the DNS or DHCP Server and get all of the computers that belong to the network.
Currently I’m running nested for loops to ping every possible IP Address however it takes way to long with over 10 subnets.
I’m trying to change from doing it like a noob to doing it like a boss.
I want to get a list of all computer names and IP Addresses as well as if their IP was assigned Dynamically or Statically.
How should I do this?

Answer 1

There is no way to enumerate all hosts on a network, even pinging all of them isn’t sufficient as some may not reply to ping. For the dynamically allocated ones you could query the DHCP server, but DHCP as a protocol does not support this, you’d have to write a daemon process and query the logs or assignment file.

If you do want to do it by pinging I’d suggest writing a small program the runs in the background and pings everything, keeping the results in memory, and then have your php script query that. This way you response time will be near immediate. So long as hosts don’t appear and disappear too frequently (sounds unlikely) then this should be fine.