The Linux kernel generally tends to cache its ARP tables here:
/proc/net/arp.
Darwin & Mac OS X, however, do not seem to follow the same convention.
So where can I find the Darwin & Mac OS X equivalent of:
/proc/net/arp?


Solution 1:

OS X doesn't cache things on /proc so there's no equivalent exposure of kernel data through the filesystem idiom.

You can call arp -a to dump the current table to the location of your choosing if that sort of DIY caching has benefits for your code or use case.

Solution 2:

It looks like the cache on OS X isn't stored anywhere. An inspection of the arp command reveals no open data files during runtime, and man 4 arp claims that the cache is dynamically created.