Interesting Arping bug report
A few months ago I was strolling in the Debian bug tracking system
and found a curious bug filed
against Arping , a program I maintain.
It said that unlike Arping 2.09, in Arping 2.11 the ARP cache was not updated after successful reply.
I thought that was odd, since there's no code to touch the ARP cache, neither read nor write. Surely
this behaviour hasn't changed?
I tried to reproduce the behaviour and sure enough, with Arping 2.09 the arp cache is updated,
while with 2.11 it's not.
$ arp -na | grep 192.168.0.123
$ # --- First try Arping 2.11 ---
$ sudo ./arping-2.11 -c 1 192.168.0.123
ARPING 192.168.0.123
60 bytes from 00:22:33:44:55:66 (192.168.0.123): index=0 time=1.188 msec
--- 192.168.0.123 statistics ---
1 packets transmitted, 1 packets received, 0% unanswered (0 extra)
$ arp -na | grep 192.168.0.123
$ # --- Ok, that didn't change the ARP cache. Now try 2.09 ---
$ sudo ./arping-2.09 -c 1 192.168.0.123
ARPI...