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dnsipttlnameservers

Is TTL (Time To live) in the IP packet in seconds or steps?

From my previous knowledge, I know that TTL is the amount of routing steps an IP packet is allowed to travel.

On DNS, we are using a IP/UDP base, and from the documentation I see that the TTL actually means the amount of seconds the data stays in the cache of the NameServer.

Am I missing something or is it both?

Thanks

Solution

  • IP TTL is in steps. Time limits, caching, and the like take place at higher levels of the protocol stack; IP doesn't know or care about them.