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garciasnyesterday at 9:43 PM2 repliesview on HN

Could it be because folks set it low for initial propagation and then never change it back after they set it up.


Replies

fukawi2yesterday at 9:50 PM

That's not how TTL works. Or do you mean propagation after changing an existing RR?

It's "common" to lower a TTL in preparation for a change to an existing RR, but you need to make sure you lower it at least as long as the current TTL prior to the change. Keeping the TTL low after the change isn't beneficial unless you're planning for the possibility of reverting the change.

A low TTL on a new record will not speed propagation. Resolvers either have the new record cached or they don't. If it's cached, the TTL doesn't matter because it already has the record (propogated). If it doesn't have it cached, then it doesn't know the TTL so doesn't matter if it's 1 second or 1 month.

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deceptionatdyesterday at 9:56 PM

Maybe, but I don't think TTL matters for speed of initial propagation. I do set it low when I first configure a website so I don't have to wait hours to correct a mistake I might not have noticed.

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