dynamic IPs & dnsmadeeasy.com & WTF

pencil

Server newie here so be gentle.

I'm reading this great boards thread : HOWTO set-up your own Web Server

I'm down as far as 'Setting Up DNS' and am reading about using 'www.dnsmadeeasy.com' to manage DNS lookup to a site (domain) running on my machine at home which is connected to the interweb via ADSL with dynamic IPs.

I'm starting to get the picture, needless to say this is over my head. I have some questions.

1. How can a domain on my machine here, which is assigned a dynamic IP every time I connect to my providers server (UTV Clicksilver), always be visible everywhere in the world? --- I thought it took days for DNS's to be updated worldwide?

2. Are 'www.dnsmadeeasy.com' claims that you domain (site) will always be live correct/true?

3. Can anyone give me more info on 'TTL (time to live)' an how it effect DNS up dates worldwide with dynamic IPs?

HELP ME SUPERMAN, I'm swimming in a deep swamp with this sh!te

I hope that makes sense - if it doesn't its back to burger flippin ;-)

Cheers

Ripwave

pencil wrote:

1. How can a domain on my machine here, which is assigned a dynamic IP every time I connect to my providers server (UTV Clicksilver), always be visible everywhere in the world? --- I thought it took days for DNS's to be updated worldwide?

DNS entries aren't "updated worldwide". The only authoritative DNS entry for any given domain is on that domains defined DNS server. So when a machine in Japan wants to connect to www.joebloggs.com, it sends out a DNS request that goes all the way to the DNS server for joebloggs.com to find the correct IP address for www.joebloggs.com.

These addresses are cached locally, so that if another user from the same ISP in Japan tries to reach the same site, they might get a cached answer, but joebloggs.com decides how long it wants it's address to be cached for - it can be 1 minute, or 1 week or 1 month. If it's set to 1 minute, then pretty much every request for that site will end up doing a full DNS lookup. That's not necessarily a bad thing for a low volume website.

2. Are 'www.dnsmadeeasy.com' claims that you domain (site) will always be live correct/true?

The claim is that the DNS entry for your site will always be available - obviously they can't control whether the actual site will be available. And it's not hard to keep a DNS server always available, so the claim is probably true.

3. Can anyone give me more info on 'TTL (time to live)' an how it effect DNS up dates worldwide with dynamic IPs?

See the answer to question 1. Dynamic DNS services typically set a low TTL of between 1 and 15 minutes, which means that local caching of your DNS name in Japan or wherever won't really have much effect. (Obviously, there'll be a few minutes lag if/when your IP address does change, but nothing significant.

I don't know about the modem provided by UTV, but the one that IOL provides has built in support for Dynamic DNS - you can set it up with a DynDNS.org account, and it will automaticaly update your DNS entry whenever the IP address changes - there's no need for any client software on your PC.

pencil

Ripwave,

Thank you very much for your authoritative answer, you couldn't have explained it better!!!!

And congrats on your 2000th post!