Chapter 17. DNS Hosting

Table of Contents

17.1. Example DNS records
17.2. Adding a wild-card hostname record
17.3. Using the Bytemark anti-spam system
17.4. Moving domains between machines using the Bytemark content DNS service

To take full advantage of the Symbiosis system, your domain needs to be configured to have Bytemark’s name servers as authority for it.

What follows only applies if our name servers are used; if that is not the case you will need to manage your DNS data outside of the Symbiosis system. Section 17.1, “Example DNS records” gives a listing of the records needed for the correct functioning of the system.

All domains which are hosted upon a Symbiosis system will have their DNS records automatically uploaded to the Bytemark Content DNS servers.

By default a set of typical records is created for each hosted domain with MX records pointing to the local system, and aliases such as www. and ftp. for convenience. If you wish you may edit the records to make custom additions or otherwise make changes to those defaults.

For the domain "my-brilliant-site.com" you will find the auto-generated DNS records in /srv/my-brilliant-site.com/config/dns/my-brilliant-site.com.txt

The DNS files are uploaded to the Bytemark content DNS service every hour, and allow you to use the full range of available TinyDNS options. These options are documented upon the Bytemark Website and in the TinyDNS documentation.

17.1. Example DNS records

This is an example of the records Symbiosis generates for my-brilliant-site.com. They are created automatically and stored in config/dns/my-brilliant-site.com.txt.

DNS records example. 

#
#  Nameserver records. 1
#
.my-brilliant-site.com::a.ns.bytemark.co.uk:300
.my-brilliant-site.com::b.ns.bytemark.co.uk:300
.my-brilliant-site.com::c.ns.bytemark.co.uk:300

#
#  The domain name itself 2
#
=my-brilliant-site.com:89.16.174.65:300

#
#  Useful aliases. 3
#
+ftp.my-brilliant-site.com:89.16.174.65:300
+www.my-brilliant-site.com:89.16.174.65:300
+mail.my-brilliant-site.com:89.16.174.65:300

#
# A record for MX 4
#
+mx.my-brilliant-site.com:89.16.174.65:300

#
# The domain name itself -- AAAA record and reverse. 5
#
6my-brilliant-site.com:200141c80001596d0000000000000065:300

#
# Useful aliases -- AAAA records only
#
3ftp.my-brilliant-site.com:200141c80001596d0000000000000065:300
3www.my-brilliant-site.com:200141c80001596d0000000000000065:300
3mail.my-brilliant-site.com:200141c80001596d0000000000000065:300

#
# AAAA record for MX
#
3mx.my-brilliant-site.com:200141c80001596d0000000000000065:300

#
#  MX record -- no IP defined, as this is done separately above. 6
#
@my-brilliant-site.com::mx.my-brilliant-site.com:15:300

1

These lines create NS and SOA records for my-brilliant-site.com pointing at a.ns.bytemark.co.uk, b.ns.bytemark.co.uk, and c.ns.bytemark.co.uk. The time-to-live for these records is 300 seconds. Note that the double colons in these records are deliberate as the IP addresses are defined elsewhere by Bytemark.

2

This creates an A record pointing my-brilliant-site.com to the IP address 89.16.174.65, and a PTR record for the reverse. Again, the TTL is 300 seconds.

3

These three lines add A records for expected aliases. Once again, the TTL for these records is 300 seconds.

4

This line adds in an A record for the MX record defined below.

5

From here the IPv6 equivalents of 2, 3, and 4 are specified, using AAAA records is used instead of an A record. Note that IPv6 addresses are specified in full, without any colons.

6

This last record creates an MX record directing mail for my-brilliant-site.com to mx.my-brilliant-site.com, with a distance of 15. The double colon is deliberate since we defined the A record for +mx.my-brilliant-site.com in <4>, and an AAAA record for the same name in <5>.

17.2. Adding a wild-card hostname record

In addition to these records for each domain, a wild-card A record is needed for the hostname such that the .testing. prefix works. If your machine is at Bytemark, this has already been setup for your machine’s Bytemark alias, for example example.vm.bytemark.co.uk.

If your machine is not hosted at Bytemark, or your hostname does not end in bytemark.co.uk then you will need to set this alias up. Adding the following line to your DNS file will work, assuming the domain is hosted at Bytemark. This assumes that your machine is called host.example.com and that your machine’s IP address is 1.2.3.4.

+*.host.example.com:1.2.3.4

17.3. Using the Bytemark anti-spam system

Bytemark Hosting offer wholesale spam protection for their hosting customers. To enable this service simply create the file /srv/my-brilliant-site.com/config/bytemark-antispam. This will update the DNS records as required as well as causing mail sent directly to your machine to be temporarily rejected, ensuring spammers cannot circumvent the anti-spam protection.

17.4. Moving domains between machines using the Bytemark content DNS service

If you wish to move your domains between two machines running Symbiosis and using the Bytemark content DNS service, you must contact Bytemark Support to arrange the domain to be moved between content DNS accounts.

This results from the necessity for ensuring that only people with the proper authorisation can change live DNS data. Once a domain has been hosted on our network, a content DNS account will have sole authority for it.

If you purchase a second server and move some of your domains onto it, or purchase a domain from another Bytemark customer you must contact us to move authority for the domain into the correct account.

Until this is done, although the Symbiosis system will be creating and uploading data it will not be to the account with the authority to make the data live.