I need to register a recently bought .com name (from a domain name auction). I am based in the UK, though I realise I need an icann approved registrar to take in the transfer.
My question is: does the location of the registrar matter and which one is the best? I will be changing the nameservers to point at the ones I use in london, which also have the dns zone files. I am wondering if there is any difference in any of the registrars in terms of speed, reliabilty, (or anything else) or whether I should just go with the cheapest?
My current domain registrar can deal with all TLDs but cannot take transfers in at the moment, so I'm looking for a good one, preferably that deals in uk currency.
I notice that there are only about 12 actual icann approved registrars based in the uk (from their website), so does everyone usually use enom, tucows etc.?
Thanks :)
So, DNS-wise, if you host your own DNS-servers, you may register with whom you like, as its location does not matter.
Price may be one factor. Doing business in the same country another one. And the hope that a registrar will stay in business over a long time may also be important, but may perhaps not be tied to the cheapest prices then ...
Kind regards,
R.
You sound like you know DNS well, I really need to understand the workings of DNS better, if you could help that would be great.
Please correct me if I have any of this wrong :)
I have private nameservers in which I can change the A, MX, CNAME, NS records - what it calls a dns zone file under its control panel.
Is this nameserver the dns-server?
I understand that all DNS lookups are done via the 13 root servers and they keep a record of all the .com names and their respective nameservers. So in the case of a .com, this would be handled by Verisign. I'm guessing these are also a type of dns-server, are their records also called zone files?
And I'm wondering about the dns propagation - is it automatic across the world to all ISP dns-servers, or does it only happen when a customer of an isp requests that page (like when i try to view my own website) and is then relayed and cached along the way?
And there are several cascaded queries to different nameservers needed to get the final result.
Yes (if your query is not already cached locally, to take some burden from the root servers), it starts with the 13 root nameservers you mention, they have a relatively small zone file where each TLD like .COM is referenced.
If you look up your own www.example.com domain, the root nameservers (e.g. A.ROOT-SERVERS.NET) will simply tell you to look for .COM at one of these nameservers A.GTLD-SERVERS.NET ... M.GTLD-SERVERS.NET.
These GTLD nameservers keep the large .COM zone file, which gets updatead by the registars, and which just has references of every .COM to their respective name servers, so another query to one of these nameservers for your www.example.com gets anwered with the information about the authoritative nameservers for example.com (and all of its sub domains).
A third query now gets to your own nameserver, where you defined your SOA/NS/A records for your own domain example.com and all subdomains *.example.com, and your nameserver finally gives out the IP address (A record) of your www.example.com.
To recap in short:
The root DNS servers are the SOA (authority) for .
The GTLD DNS servers are the SOA for the com. zone
Your own DNS servers are the SOA for the example.com. zone.
So, to answer you last question:
While there is some transfer between the redundant servers of their own level (to keep their zone files current), there is no transfer or active propagation between the different DNS servers (except for a possible passive cacheing by local resolvers on the visitor's end), each party has its own responsibility.
Your registrar has to update the COM zone file, if you switch your name servers for your .com domain, but he does not even need to know if you update your local zone file for switching your webhost's IP address or to add another subdomain name.
Kind regards,
R.
So when a registrar states that your DNS record may take up to 48 hours to propagate, what is happening here? Is the record uploaded to the GTLD being propagated, sent out to local ISPs DNS servers? Or is it that local ISPs have a cache that expires after 48 hours, and then checks the GTLD? Does it check for all updates on GTLD, or only ones requested by users?
I'm wondering if lesser known websites only get their nameservers cached at an ISP DNS server if somone using that particular ISP looks for the website, when it comes back through as a request from GTLD but isn't currently stored?
I've read articles on the internet that say the propagation is to do with caching DNS information at the ISP, but then to cache every website DNS must take up huge amount of space?
So when a registrar states that your DNS record may take up to 48 hours to propagate, what is happening here? Is the record uploaded to the GTLD being propagated, sent out to local ISPs DNS servers? Or is it that local ISPs have a cache that expires after 48 hours, and then checks the GTLD? Does it check for all updates on GTLD, or only ones requested by users?
Yes and no. When your registrar initiates an update in the GTLD zone, updates go active dynamically, and your new DNS records are available very soon.
However, nothing gets actively "sent out" to ISP resolvers. It is a pull service. And as you assume, it may take some time, until local users' DNS resolvers' caches get cleared (actual caching time is influenced by your own zone's TTL defintion). These "48 hours" are a rule of thumb when even the last possible Joe User should finally be able to see your changes through his local resolver's chaches.
I'm wondering if lesser known websites only get their nameservers cached at an ISP DNS server if somone using that particular ISP looks for the website, when it comes back through as a request from GTLD but isn't currently stored?
I've read articles on the internet that say the propagation is to do with caching DNS information at the ISP, but then to cache every website DNS must take up huge amount of space?
There is not much magic within these caches. The cache space is just for the mostly used and most recent records (not "nameservers"), as they just cache what they see flying by based on their users' requests, so the next requestor may get an instant reply from a cached information for convenience, instead of going out to place a recursive query.
When changing your nameservers, you can easily watch the updating/propagation process at the different levels from the GTLD root servers down to a local ISP's resolver by explicitly querying these nameservers with dig or nslookup.
`dig @nameserver www.example.com`
Kind regards,
R.
