2 ms·
Traceroute’s trick is amusing. It abuses the TTL field, sending out packets with too-low TTLs and waiting to see who complains about them. When layers reveal th
by closeparen 6y ago
Traceroute’s trick is amusing. It abuses the TTL field, sending out packets with too-low TTLs and waiting to see who complains about them. When layers reveal themselves they are doing it voluntarily, and those wise to the game can choose not to participate, or to troll it.
https://www.theregister.com/2013/02/15/star_wars_traceroute/ https://www.theregister.com/2013/02/15/star_wars_traceroute/
- m3047 6y agoThose are IP packet TTLs. Also useful in some cases for diagnosing mysterious RSTs and SYNs. Also useful in some cases to purposefully set low if there is route flapping.
- Tepix 6y agoIt's not abusing the TTL, it's working as designed
- closeparen 6y agoAFAIK the design purpose of TTL is to prevent an infinite loop in case the route contains a cycle.
- allarm 6y agoThe IP TTL field is unrelated to the topic - DNS and IP are sitting on the different OSI layers. Also, the traceroute command does not abuse this field, it’s just the way the IP protocol works. I.e. eBGP sets TTL to 1 by default, to prevent establishing relationships with the neighbors further that one hop away.