At 13:54 -0500 1/17/05, Joe Abley wrote:
So the TTLs of records in the registry-operated zones will likely have no impact on how long NS records for delegated zones remain in caches.
If panix (or anybody else) wants to increase the time that their NS records stay in caches, the way to do it is to increase the TTLs on the authoritative NS records in their own zones. For panix.com, these appear to be set to 72 hours (the non-authoritative NS records for PANIX.COM in the COM zone have 48-hour TTLs).
That's provided that the panix.com authoritative NS's are seen in the cache. Not all name servers return the authoritative NS's in an answer. (BIND has an option 'minimal-responses yes_or_no;' that control this. The default is no, but I know of one "yes" user.) The registrant's copy of the NS set is more credible (RFC 2181 speak) than the registry's copy, so if a cache sees both, the cache tosses the registry copy. But there's no guarantee that the cache will see both. Usually it does though. -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Edward Lewis +1-571-434-5468 NeuStar "A noble spirit embiggens the smallest man." - Jebediah Springfield