I want to get the mac addresses for all hosts on a given subnet. So far I force an arp table update by pinging all ips involved. After that I query the arp table and everything is fine.
The problem is how to improve the update speed. Pinging 65000 addresses takes about 15 minutes on an iPhone 3GS. Even if I do not wait if a response is happening. Thats way to long.
It may be that there is a bug in my ping code that is slowing things down, but I could not find any so far.
My question is:
Is there a faster network operation that triggers an arp table update?
Can’t you do something with multicast on the current subnet, preferably something that generates
ACKnowlegements so that if you listen on the interface, you’ll discover all the mac addresses.