Just remember that you need to make the TTL changes well before you make the actual A/MX record changes.
The time in advance depends on your current TTL (usually 48 hours). Unfortunately, there are alot of broken DNS servers that don't properly honor your TTL and will cache for a longer period of time. Given that, it is best to change your TTL to a short value (3600 seconds) at least a week in advance of changing an IP address. Some DNS folks frown on a TTL set to 60 seconds. Makes for a lot of traffic on a busy domain. John ----- Bruce Robertson <[EMAIL PROTECTED]> wrote: > If you have control over the SOA record for the names, then what you > can > do is set the TTL to 1 minute. Then, wait however long the current > TTL > is so that the whole world picks up the new TTL. You can then make > the > change, and your downtime will be no longer than 1 minute. You can > then > restore the TTL to whatever you want. > > Bruce Robertson, President/CEO > +1-775-348-7299 > Great Basin Internet Services, Inc. company-wide fax: > +1-775-348-9412 > http://www.greatbasin.net my efax: > +1-775-201-1553 > > > > Anna wrote: > > Hi. > > > > I have DNS and SMTP servers running on a machine connected to the > > internet, and I'm changing ISPs today... so I need to change the IP > of > > this machine. I think my real problem is with the DNS server.. > > > > The DNS server is the repository the info of a couple domains. The > DNS > > servers at a (third, unrelated) ISP provides the actual > authoritative > > DNS service (these servers are named by the registrar) but they > query my > > machine for information updates. I really like this setup, but the > > problems involved with changing ISPs makes me question the > practicality. > > > > My DNS server names the MX records for my domains. Which means, > the > > SMTP servers will have some down-time while the cached DNS records > out > > there get updated. This is bad, but I think unavoidable. > > > > This whole difficulty has me thinking it would be worth the while > and > > cost to move these services off my little server and to some > hosting > > company. I do not have time to do this now, so I have to deal with > this > > little mess myself. > > > > ---------------------------------------------------- > > > > This has me wishing for a way to give a machine two default routes. > One > > would have a higher priority than the other for outgoing > connections, > > but incoming connections would be handled for their duration on the > > device that originally accepted the connection. It seems like this > > should be a possibility, but I have never heard of a setup like > this. > > Is it possible? > > > > If this is not possible then I just have to bite the bullet and > accept > > some down-time... I think. Unless anyone of you has an idea. I'd > love > > to hear it. :) > > > > Thanks, > > > > - Anna > > > > > > _______________________________________________ > > RLUG mailing list > > [email protected] > > http://lists.rlug.org/mailman/listinfo/rlug > > > > > > > > > > > > _______________________________________________ > RLUG mailing list > [email protected] > http://lists.rlug.org/mailman/listinfo/rlug -- John Dell UNR/CASAT [EMAIL PROTECTED] http://www.casat.org/ _______________________________________________ RLUG mailing list [email protected] http://lists.rlug.org/mailman/listinfo/rlug
