Comment by tharkun__
16 hours ago
No it doesn't. DNS breaks as soon as TTLs run out. It's your choice to set them so low that stuff breaks immediately.
16 hours ago
No it doesn't. DNS breaks as soon as TTLs run out. It's your choice to set them so low that stuff breaks immediately.
Unfortunately you can't set DNS TTL arbitrarily high (or low) without some resolvers ignoring your suggestion and using arbitrary values.
Most historical outages lasted minutes or hours. One arguably lasted much longer, when someone lost control of their servers due to civil war.
I haven't followed this closely, but have there been any... shall we say plain outages longer than six hours? That's not an outrageous TTL. Or a day.
What do you recommend then? DNS doesn't usually change that often, but if you mess it up when it does, you're in for some pain if TTLs are high!
Not the one you're replying to, but I'd keep TTL high normally and lower it one TTL ahead of a planned change.
I would define high as "double time needed to fix a dns issue" and account for weekends
This is the way.
This assumes that the host name you want has been recently queried. If it's not cached, good luck...