Determine MAC address based on IP address - Delphi, Lazarus, Free Pascal https://www.tweaking4all.com/forum/delphi-lazarus-free-pascal/determine-mac-address-based-on-ip-address/ Tweaking4All.com Discussion Board en-US Wed, 10 Jun 2026 00:37:54 +0000 wpForo 60 Determine MAC address based on IP address https://www.tweaking4all.com/forum/delphi-lazarus-free-pascal/determine-mac-address-based-on-ip-address/#post-364 Mon, 25 Apr 2016 05:37:42 +0000 I hate entering a MAC Address, especially when I already know the IP address.

With this little trick (tested on MacOSX and Linux, but will probably also work under Windows), you can retrieve the MAC address of another computer in your network.

$ ping -c 1 192.168.1.10
PING 192.168.1.10 (192.168.1.10): 56 data bytes
64 bytes from 192.168.1.10: icmp_seq=0 ttl=64 time=313.632 ms
--- 192.168.1.10 ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 313.632/313.632/313.632/0.000 ms
$ arp 192.168.1.10
aftv_bedroom (192.168.1.10) at 0:2b:3a:4f:69:ba on en0 ifscope

The ping is sometimes needed to avoid getting this with Arp:

$ arp 192.168.1.10
192.168.1.10 (192.168.1.10) -- no entry
]]> Delphi, Lazarus, Free Pascal Hans https://www.tweaking4all.com/forum/delphi-lazarus-free-pascal/determine-mac-address-based-on-ip-address/#post-364