DNS question....

[devolution]

:embarrass

The three letters that strike fear in even the most hardened hack!

I'm wondering about my domain.
I have got the 2 Nameservers for my webserver (listed as Primary/Secondary for the domain).

Now, I'm thinking of adding MyDomain.com entries in the Nameservers - so if my webserver ever goes down, it can at least point to a page on an alternative webserver.

For example, I have the following NS entries at the moment:

dns1.synuk.com
dns2.synuk.com

which point to my webserver.

If I were to change it to:

dns1.synuk.com
dns2.synuk.com
ns1.mydomain.com
ns2.mydomain.com
ns3.mydomain.com

Would the MyDomain entries work ONLY if the synuk.com webserver was down?

 

[DotComster]

No - but only semi-sure here.

I have no idea what 3 to 6 are used for, but only the first 2 are used to spefify where a site is hosted.

 

[Anthony Ng]

More registrars are allowing more than 2 nameservers to be listed. Please also keep in mind that the Internet is a web of networks where accessibility to the first 2 servers is good for Californians at this moment but not for our cousins in Southern France a few seconds later. So it always helps to have more redundant servers configured.

 

[mole]

Interesting post on redundancy.

Nameservers are configured to be pretty stable, particularly if you are going with mydomain or eNOM or some of the other reputable registrars.

Even Verisign has just introduced their souped up DNS service, and promises full reliability for $24 bucks a year. But then again, server downtime is probably a bigger issue than NS.

 

[NameBox]

Mole: Given the stability of nameservers, what do you think of the business prospects of those companies offering DNS services on a yearly fee basis of $25-50.00. It seems that this would be a redundant service, or am I wrong here ...

 

[mole]

DNS is a minefield for those not into these things, Box. A company that packages their services in a language that appeals to the unwashed masses will have a ready market, IMO.

Right now, mydomain seems to be doing a great job in that area. It remains to be seen if they will eventually charge for it.

 

[Bob]

Originally posted by devolution
:embarrass

If I were to change it to:

dns1.synuk.com
dns2.synuk.com
ns1.mydomain.com
ns2.mydomain.com
ns3.mydomain.com

Would the MyDomain entries work ONLY if the synuk.com webserver was down?

I am fairly certian this is true. The DNS Servers are listed in the zone files in order in which they are queried. That is the point of having a primary, secondary, teriary, etc.

When you go to a website, your ISP queries the primary DNS server. If that is down, it goes to the secondary. If both of those are down, it keeps going down the list.

So, by setting mydomain as your 3rd, 4th, 5th, and 6th DNS servers, they will only be hit if your original two are down.

One way to verify this is to set mydomain to go to a separate URL and type your domain into the broswer and see where you end up.

-Bob

 

http://cr.yp.to/djbdns/third-party.html

 

[NameBox]

Nice article Goh! Shame about your Mao avatar, what with the Cultural Revolution and all ....:sad:

 

Thx.net for liking my post. Regarding the chairman avatar, old man brain does not function as well and sure mistakes were made! I use that avatar for two points, I am from Hong Kong of China and I dream to be a Chairman (cause I am poor) and not for the purpose of worshiping him.

 

[NameBox]

Evidently, Mao had one of the largest head circumferences and biggest (in size ) brains ever recorded. A true watermelon of a head. Maybe this explains the later "mistakes". So much oxygen needed to feed that big brain ....

Maybe you should have an animated avatar GIF, cycling through Mao, Deng, Jiang, .... to the true Chairman of $$$ ... Li Ka Shing, given your residence in HK!

 

[jimr]

Originally posted by DotComster
No - but only semi-sure here.

I have no idea what 3 to 6 are used for, but only the first 2 are used to spefify where a site is hosted.

No 3 to 6 are use for the same thing as 1 and 2. To resolve a name. All of the name servers are used in no specific order.

You can actually have up to 13 name servers and some registrars allow you to have that.

/jim

 

[jimr]

Originally posted by Bob


I am fairly certian this is true. The DNS Servers are listed in the zone files in order in which they are queried. That is the point of having a primary, secondary, teriary, etc.

When you go to a website, your ISP queries the primary DNS server. If that is down, it goes to the secondary. If both of those are down, it keeps going down the list.

So, by setting mydomain as your 3rd, 4th, 5th, and 6th DNS servers, they will only be hit if your original two are down.

One way to verify this is to set mydomain to go to a separate URL and type your domain into the broswer and see where you end up.

-Bob

Name servers are not queried in any special order. Normally several name servers are queried at the same time and you use the first answer you receive.

The name primary/secondary/tertiary is very misleading and is often a cause of misunderstanding. It's better to use master and slave servers which better shows what it is about.

When you send a query for the NS of a zone you normally receive the answer in a random order.

If somenone wants a failover service I believe Zoneedit can provide that for a smaller fee

/Jim

 

[pixelman]

Originally posted by NameBox
Mole: Given the stability of nameservers, what do you think of the business prospects of those companies offering DNS services on a yearly fee basis of $25-50.00. It seems that this would be a redundant service, or am I wrong here ...

Usually I set the DNS entries to point to mydomain.com's DNS (can be set in your registrar's domain control panel). I don't pay a single cent, especially to NetSol, on domain parking service.