3 ms·
How does ICMP routing work? I always wondered about that. There's no port in ICMP, how does OS understand which ping executable receives ICMP echo replies.
by vbezhenar 5y ago
How does ICMP routing work? I always wondered about that. There's no port in ICMP, how does OS understand which ping executable receives ICMP echo replies.
- toyg 5y agoIf I read this [0] correctly, there is still a hashmap of sorts. [0] https://flylib.com/books/en/3.475.1.74/1/ https://flylib.com/books/en/3.475.1.74/1/
- zamadatix 5y agoICMP has an identifier field and a sequence number field, both exist to aid in matching requests with replies.
- vbezhenar 5y agoThanks. It seems that's not exactly correct. ICMP has type, code and checksum fields. Rest of data is type-specific. But echo-request and echo-reply types do have identifier and sequence fields indeed.