Knowledge base Domain names
Whilst internally the internet uses IP addresses, the way people interact with the internet uses names. We use names like www.aaisp.net.uk to get to a web site, or sales@aaisp.net.uk to send an email. These names are called host names or domain names (there is no practical difference between the terms). For a web site the first part after the http:// is the domain name, usually starting www. For email the domain name is the bit after the @.
In order to acess a web site or send an email or anything else which uses a name, the name has to be turned in to an IP address or other information that can be used to actually make the connection accross the internet. This conversion is called resolving.
We provide two resolvers for customers to use. If you have to set up your computer manually with these (refered to as "DNS servers") they are 217.169.20.20 and 217.169.20.21. We also have IPv6 resolvers.
We also sell domain names. A domain name, such as example.com is registered with a registry. We deal with several registries, such as Nominet (for domains ending .uk). In general, within certain rules, any domain that does not yet exist can be registered. However the domains have to be part of a parent domain. So a domain ending .co.uk is handled by Nominet and you can have anything you like followed by .co.uk that nobody else has. The domain you get would have letters, numbers and maybe a hyphen. In most cases two letter domains are not allowed and there are a few other restrictions.
Once you have the domain you can create any subdomains under it, these are more bits that then have a dot then your domain. So if you had example.com you can have thisisan.example.com as a sub domain. You can have sub domains of sub domains, so even this.is.an.example.com could be used if you wanted.
Once you have a domain you need to have authorative DNS servers. These are servers which tell the rest of the world what information you have associated with the domain. For example, if you had example.com you might have decided that www.example.com would have an IP address of 10.20.30.40. This means when anyone tried www.example.com in a web browser they would connect to IP address 10.20.30.4 to get the web page. The DNS servers are what hold that information and tell any computer in the world the answer if they ask. The registry is who tells them which DNS servers to ask in the first place.
We have two authorative DNS servers called primary-dns.co.uk and secondary-dns.co.uk. If you have a DNS service from us you can edit the domain records using a web page on our control pages. There is more information on the control pages about the different types of record you can set up.
We have two other services associated with domains - these are email and web space.
When you register a .uk domain you are entering in to a contract with the registrar (Nominet) and we act as you agent in dealing with Nominet. The domain is registered in your name, not ours.
Secondary and Reverse DNS
Secondary DNS
If you are running your own DNS, you will need a secondary. You can use secondary-dns.co.uk which is configured to try and automatically secondary any new domain from an AAISP allocated IP address that a customer uses.
Using our secondary name server is normally automatic if you are using BIND-8/9. To make it pick up a domain automatically you have to change the top level delegation to list your name server and secondary-dns.co.uk, and then have bind send a notify from your primary. Our name server checks the delegation first and then adds the zone, loading from your primary servers IP. If you later change the IP of your primary, then the old IP must return that it is not authoritative in order to clear the zone allowing it to reload from the new primary. If you encounter any difficulties, please contact technical support, who can make changes manually if necessary.
Reverse DNS
Reverse DNS is the system by which you can give a name to each of your IP addresses. Normally DNS gives an IP address to a name, but reverse DNS is the other way around. Sometimes it is necessary to have a name associated with an IP address, and then have that IP address correctly associated with a name. This is because some systems and tools on the internet will check the address (e.g. some ftp servers and some email servers). You should only set reverse DNS to domain names you control.
The way this works is that the IP address is turned in to a domain, e.g. 217.169.0.1 would be turned in to 1.0.169.217.in-addr.arpa. Any machine wanting to know the name for 217.169.0.1 would look up the PTR DNS record on 1.0.169.217.in-addr.arpa.
We are delegated the address blocks we control by RIPE, e.g. we manage 0.169.217.in-addr.arpa. (and many others). If you had, for example, a block of addresses from 217.169.0.0 to 217.169.0.3 then you might want to give names to those addresses.
This may sound rather complicated, but we have several ways to manage your reverse DNS as follows.
Reverse DNS from forward DNS
If you have a domain with us, you can create entries in the domain tagged as A+reverse rather than just A. This tells our DNS server to automatically fill in a PTR record the other way around. This is the simplest way to set specific names for each IP on your network.
Auto-reverse name
By default we create a reverse entry and a matching forward DNS entry so that your IP has a name associated with it. This is set up in our control pages as auto reverse DNS.
Reverse DNS by NS records
We can delegate the reverse DNS for each of your addresses. This means you would have a zone file for each IP, e.g. 0.0.169.217.in-addr.arpa., 1.0.169.217.in-addr.arpa., 2.0.169.217.in-addr.arpa., 3.0.169.217.in-addr.arpa. each of which would contain one PTR record identifying the name of the machine. Remember that you also have a WAN address which may be completely different from your other addresses, and the reverse DNS is also delegated to your name servers for this too.
To do this, simply put one or two name servers in the settings under http://control.aaisp.net.uk/ for your ADSL RADIUS settings, and select the NS option.
Reverse DNS by CNAME
We can also delegate the reverse DNS using CNAME records. This allows you to manage your DNS using only one zone file instead of one for each IP address. In the above example this would mean we have a CNAME record pointing 0.0.169.217.in-addr.arpa. to 0.0-3.0.169.217.in-addr.arpa., and 1.0.169.217.in-addr.arpa. to 1.0-3.0.169.217.in-addr.arpa. and so on. We then delegate 0-3.0.169.217.in-addr.arpa. as a zone to you and you can create PTR records for 0, 1, 2 and 3 within that zone.
Your WAN address and any other single addresses are still individually delegated as their own zone as above.
To do this, simply put one or two name servers in the settings under http://control.aaisp.net.uk/ for your ADSL RADIUS settings, and select the CNAME option.
Reverse for /24 or larger
If you have a block of 256 addresses or more, then reverse DNS delegation is done at the /24 level and setting CNAME or NS has the same effect. This means you are responsible for an entire reverse zone without the need for special CNAME entries, etc. Most people do not have such a large block of addresses.
Web based edit of reverse settings
Using the CNAME method above we can create reverse DNS zone on our primary DNS server. We can set this up with a password in the same way as any other domain, allowing you to edit the zone using the web based control pages at http://control.aaisp.net.uk/ . This way you don't need to run your own DNS servers.
To do this, ask technical support to set up the domain for you and provide a password.
Reverse DNS for IP6 addresses
If you have an IP6 assignment from us then you can set up reverse DNS in the same way. You can create forward entries that are AAAA+reverse which will automatically create reverse DNS entries in the same was as A+reverse as shown above. We can also delegate reverse DNS to you.
Choosing a UK domain
A domain ending in .uk is included in the price of your service (contact us to choose a domain), and we provide SMTP and IMAP/POP3 mail handling for the domain as you require. If you have not already chosen a UK domain then this may be useful as a guide to what domains are available and what they mean.
Firstly, it is important to realise a domain can only contain letters a-z numbers 0-9 or hyphens, and no part can end or start with a hyphen. Also, domains that are only 2 letters (e.g. aa.co.uk) or one character are not valid (except the few that are currently registered). You should use a sensible name and not one that is someone else's trademark as there are procedures for domains to be challenged.
| .co.uk | This is probably the most well known. It is intended for companies although there is no formal restriction or checking to stop you registering it for personal use. |
| .org.uk | This is intended for non profit organisations. Again, there are no formal restrictions - but using an org.uk would give the message that you are a non profit organisation. Some people will register an org.uk the same as their co.uk to avoid confusion, redirecting web traffic and email for the .org.uk to the .co.uk and not publishing the org.uk domain itself. |
| .me.uk | This is intended for personal use, and is typically yourname.me.uk or yoursurname.me.uk. Remember, if you get your surname then you can create subdomains for no charge, e.g. firstname.surname.me.uk and set up mail, e.g. firstname@surname.me.uk. As such .me.uk is ideal for personal use. Being quite new there are many names available. Businesses should not register .me.uk domains as there are specific rules that make such registrations "abusive" and could mean your domain is challenged. |
| .ltd.uk | This is specifically for UK limited companies (not plc's) and the domain has to exactly match your company name at companies house. Invalid characters such as spaces and brackets can be ignored or have a hyphen instead. However the domain is manually checked before it is registered and the rules strictly applied. |
| .plc.uk | As ltd.uk for plc's. |
| .net.uk | This is only available to ISPs. Unlike .net where it is intended for ISPs but there is no formal checking, .net.uk is specifically for ISPs and applications are checked. You need an AS number or an LIR tag to register (if you don't know what these are then you are not an ISP). You also have to convince nominet that you are genuinley an ISP. |
| .ac.uk | This is for colleges and universities. The rules are a bit complex and we can submit a request if you are a university or a college. Some societies which do training and education qualify. |
| .sch.uk | This is for UK schools only and the name is picked for you by the LEA. We provide .sch.uk domains to schools free anyway. |
| .police.uk | Forget it unless you are a police force |
| .gov.uk | Goverment bodies |
| .mod.uk | You can guess this one I am sure |
| .nhs.uk | And this one |
| .parliament.uk | And this one |
| .nic.uk | Nominet (who manage the .uk name space) |
You can check any UK name availability at http://www.nic.uk/ and if it is free, ask us to register. A name reported as "DETAGGED" is not available, it must be not found.
