Comment by loeg

I was interested in a related topic a while back.

Historically, to receive ICMP packets, I think you had to open a RAW socket and snoop everything. Obviously, this required root or similar.

IPPROTO_ICMP allows you to send ICMP packets and receive responses from the same address, without root. But you can't use it for traceroute because it only accepts ICMP responses from the ultimate destination you sent to; not some TTL failure intermediary.

Finally, IP_RECVERR (Linux 2.2) on UDP sockets allows you to receive associated ICMP errors from any hop for a send. (This is useful for traceroute, but not ICMP ping.)

I think there are also some caveats on how you can monitor for these type of events in Rust in particular? IIRC, the mainstream async stuff only watches for read/write events, and these aren't those.