When are DNS Server Updated?

[chickendippers]

I'm just wondering if ntl: sets a specific time each day when they update their DNS servers to take account of people changeing their domain's DNS.
This would be very usefull, especially to me as I would like to know when I will be able to see my website via my domain :)

[Chris]

I'm just wondering if ntl: sets a specific time each day when they update their DNS servers to take account of people changeing their domain's DNS.
This would be very usefull, especially to me as I would like to know when I will be able to see my website via my domain :)

No idea, but you don't have to use NTL's DNS if you know the IP of an alternative. Just drop that into your IE settings instead (and I don't know how to do that either, I use a Mac).

[badnbusy]

actually the DNS servers are not entered into IE setting. You need to go to control panel - network connection - right click your connection..properties... - double click TCP/IP and in the bottom two boxes, put 2 other DNS IP's in :)

[Paul]

I'm just wondering if ntl: sets a specific time each day when they update their DNS servers to take account of people changeing their domain's DNS.
This would be very usefull, especially to me as I would like to know when I will be able to see my website via my domain :)

DNS doesn't work like this. Nobody updates their dns servers at a specific time. Basically all dns records have an expiry time and when a record has expired, it is re-newed from the domains primary dns when next requested. :)

[kronas]

I'm just wondering if ntl: sets a specific time each day when they update their DNS servers to take account of people changeing their domain's DNS.
This would be very usefull, especially to me as I would like to know when I will be able to see my website via my domain :)

the usual time for a site to appear is 24 to 48 hours, although with NTL you just dont know :erm: :D :p:

[chickendippers]

DNS doesn't work like this. Nobody updates their dns servers at a specific time. Basically all dns records have an expiry time and when a record has expired, it is re-newed from the domains primary dns when next requested. :)Ah cool. From what other people have told me elsewhere I assumed that was how it worked (I guess they were over simplifing/just plain wrong) is there anyway to find out when the dns records expire?

[Paul]

Ah cool. From what other people have told me elsewhere I assumed that was how it worked (I guess they were over simplifing/just plain wrong) is there anyway to find out when the dns records expire?

Yes, nslookup will tell you if you run it in "debug" mode.

For example - if I try it for CF I get this ;

QUESTIONS:
www.cableforum.co.uk, type = A, class = IN
ANSWERS:
-> www.cableforum.co.uk
canonical name = cableforum.co.uk
ttl = 359 (5 mins 59 secs) -> cableforum.co.uk
internet address = 69.72.137.98
ttl = 359 (5 mins 59 secs)
AUTHORITY RECORDS:
-> cableforum.co.uk
nameserver = ns1.i-webserver.co.uk
ttl = 41950 (11 hours 39 mins 10 secs)
-> cableforum.co.uk
nameserver = ns2.i-webserver.co.uk
ttl = 41950 (11 hours 39 mins 10 secs)
ADDITIONAL RECORDS:
-> ns1.i-webserver.co.uk
internet address = 69.72.137.100
ttl = 67553 (18 hours 45 mins 53 secs)
-> ns2.i-webserver.co.uk
internet address = 69.93.128.72
ttl = 67553 (18 hours 45 mins 53 secs)

You can see (highlighted) that CF's dns entry will expire on just under 6 minutes time in the dns server I use. :)

[Chrysalis]

well ntl's dns server seem to be pretty quick when it comes to updating domain's but I disagree with that all dns server will auto update when domains ttl expires, when I was using freeserve years ago domains used to take WEEK's to propogate.

[badnbusy]

You could always try using a different PROXY. This has its own DNS servers, and will probably be faster

[Paul]

well ntl's dns server seem to be pretty quick when it comes to updating domain's but I disagree with that all dns server will auto update when domains ttl expires, when I was using freeserve years ago domains used to take WEEK's to propogate.

Well you are free to disagree if you wish - but that's still how dns works. :)

[chickendippers]

That's great thank you :)

[Chrysalis]

Pem thats how it is meant to work, but I was just pointing out some dns servers around the world are faulty, wether they are set to ignore ttl value's or are simply malfunctioning I dont know, but there are faulty ones out there. I work with lots of domains and run my own nameservers for hosting I do and when I update subdomains some isp's take forever to notice the changed even tho my update time should only be 15mins I am seeing some people taking over a week to see the change. Of course this is off topic and I apologise, in this case ntl dns servers get the changes fine.

[Paul]

Pem thats how it is meant to work, but I was just pointing out some dns servers around the world are faulty, wether they are set to ignore ttl value's or are simply malfunctioning I dont know, but there are faulty ones out there. I work with lots of domains and run my own nameservers for hosting I do and when I update subdomains some isp's take forever to notice the changed even tho my update time should only be 15mins I am seeing some people taking over a week to see the change.

I have never seen a dns server do this, they must be faulty in some way and the users of them should really complain.

[Scott MacVicar]

They're meant to obey TTL.

Personally I add entries to my
/etc/hosts on my linux box
and
c:/winnt/system32/drivers/etc/hosts

So it resolves instantly.

Another tip.
Update your 2nd nameserver first and wait 2-3 days and then update your first nameserver, no one will notice its down but it might cause confusion with non static content like forums.

[dev]

I have never seen a dns server do this, they must be faulty in some way and the users of them should really complain.
dns servers can be set to keep a domain cached for a set period and override the actually ttl of the domain

[Paul]

dns servers can be set to keep a domain cached for a set period and override the actually ttl of the domain

Why would anyone want to do such a thing, bizarre. :dozey:

[rince]

I have been running DNS servers using BIND of various versions for the last 10 years, and it never ceases to amaze me the number of messages I get every day in our logs about badly configured DNS servers out there.

My biggest gripe at the moment with DNS is the spate of Scandinavian broadband users who for some reason have picked our servers for their primary DNS! :(