TTLs on A records?
online-reg at enigmedia.com
Thu Apr 30 22:29:01 UTC 2009
Hi All: I'm running Bind 9.5.0-P1 / Fedora on my primary NS.
Are TTLs on individual A records universally supported?
I have a domain with a TTL of "3h", and I wanted to route traffic between
two servers in that domain quickly, so I set the TTL to the A record like:
www 300 A 22.214.171.124
;www 300 A 126.96.36.199
so I could uncomment one and comment the other to manually switch between
I've had that setup for several weeks during testing...and I just reversed
the records, incremented the serial, and reloaded BIND.
On my secondary NS (Bind 9.5.0-P1 / Freebsd 7), when I dig the "www" record,
I see the TTL counting down from 300 (Cool!), and after it reaches "0", the
IP address resets to the new one....perfect!
On my Windows DC (server2008), the change was also picked up after 5
When I use some other lookup services, however (like samspade.org), the old
IP address shows up for much longer...like it's caching it and ignoring the
TTL for the record. Should I expect that behavior?
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