it does take about 24 hours to get all the way around the world, but you will find zone transfers to regional dns servers can happen almost instantly. for example, if i update my external dns hosted here in london and reload, the new records are correctly served by DNS servers in other parts of the UK before i have time to say 'nslookup'.
the trick with DNS is to be prepared, always know in advance when a change needs doing so you can crank the ttl down (typically to 900 seconds) before making the change. better still, NAT your public addresses to a private address space with a firewall and then you can move your internal hosts around much as you like without changing the external DNS. the only time you need to plan ahead is for adding new public addresses. dan. > -----Original Message----- > From: Tom Meunier [mailto:[EMAIL PROTECTED]] > Sent: 11 January 2002 17:16 > To: Exchange Discussions > Subject: RE: DNS Changes take how long > > > I stand by my contention that it will take on average > 1/2[TTL]. If the TTL is 60 seconds, it will seem immediate > (but given a statistically significant sample will actually > average 30 seconds). Surely you're not saying that every > caching DNS server in the world clears its cache at midnight EST? > > > -----Original Message----- > > From: Daniel Chenault [mailto:[EMAIL PROTECTED]] > > Posted At: Friday, January 11, 2002 10:43 AM > > Posted To: MSExchange Mailing List > > Conversation: DNS Changes take how long > > Subject: Re: DNS Changes take how long > > > > > > Supposed to happen every 24 hours at midnight EST. Give it 24 > > hours after > > that to propogate. > > > > ----- Original Message ----- > > From: "Tony Hlabse" <[EMAIL PROTECTED]> > > To: "Exchange Discussions" <[EMAIL PROTECTED]> > > Sent: Friday, January 11, 2002 9:58 AM > > Subject: DNS Changes take how long > > > > > > > > > > Well we are making the switch from a Eudora email server to > > a Exchange > > 2000 > > > setup. The new Zone records will be sent to our ISP Verio. > > We are hoping > > all > > > updates to other DNS servers will in place by Monday. > > Anybody think it > > will > > > take longer than 48+ hours. We make the change request > > today at noon. > > > > > > > > > _________________________________________________________________ > > > Send and receive Hotmail on your mobile device: > > http://mobile.msn.com > > > > > > > > > _________________________________________________________________ > > > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > > > Archives: http://www.swynk.com/sitesearch/search.asp > > > To unsubscribe: mailto:[EMAIL PROTECTED] > > > Exchange List admin: [EMAIL PROTECTED] > > > > > > > _________________________________________________________________ > > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > > Archives: http://www.swynk.com/sitesearch/search.asp > > To unsubscribe: mailto:[EMAIL PROTECTED] > > Exchange List admin: [EMAIL PROTECTED] > > > > _________________________________________________________________ > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe: mailto:[EMAIL PROTECTED] > Exchange List admin: [EMAIL PROTECTED] > _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe: mailto:[EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED]
