Bind updating outside zone adult singles dating warner robins georgia
If one of the mail hubs or a major web server or FTParchive -- like the film library -- is moving, though, a day's loss of connectivity may be unacceptable.In cases like this, the administrator should plan ahead and reduce the TTL on the data to be changed.You should also know that when giving out answers, a slave supplies the same TTL a primary master does -- that is, if a primary gives out a TTL of one hour for a particular record, a slave will, too.The slave doesn't decrement the TTL according to how long it's been since it loaded the zone.A name server caching the old address record just before the change could have the wrong address for as long as three hours.
If the slave name server has reached the expiration time for the zone, it expires the whole zone.The drawback to this approach is that your name server will be answering a lot more queries since the querying servers will cache SOA record -- ostensibly the minimum TTL for the zone on pre-BIND 8.2 name servers -- is higher. If older BINDs followed the original DNS RFCs to the letter, the TTL field in the SOA record would really define the minimum TTL for all resource records in the zone.Thus, you could specify only explicit TTLs larger than this minimum.Suppose we know that one of our hosts is about to be moved to another network.This host houses the film library, a large collection of files our site makes available to Internet users.
By reducing the TTL, we force the outside servers to update their data more frequently, which means that any changes we make when we actually move the system are propagated to the outside world quickly. Unfortunately, we can't safely use a TTL of zero, which should mean "don't cache this record at all." Some older BIND 4 name servers can't return records with a TTL of zero, instead returning null answers or SERVFAIL errors. The easiest change is to lower the TTL in the $TTL control statement in the to each resource record.