Domain Names

dotCommunity offers all website administrators the ability to use an externally owned domain to access their website.

Initially every website created within the dotCommunity service is given a unique URL to address their website within the domain of the service provider. For example if a dotCommunity instance at the domain dotcommunity.org provided a website for an organisation called Cambridge Open Systems who chose the URL stub "cos", the full URL would be http://dotcommunity.org/cos. This would be the default way of navigating to the site. However many organisations have their own domain which they pay for independently which they would like to use for their dotCommunity website. dotCommunity allows websites the ability to do this.

Setting up a dotCommunity website to use an external domain is a two step process:

1. The service needs to be made aware of the external domain and which website is to be addressed by it.
2. The owner of the domain needs to configure the DNS to point to the dotCommunity service.

You should complete step 1 first. dotCommunity will not start using the configured domain name until it detects that the DNS has been configured correctly. However, if you set up the DNS before configuring the dotCommunity service then the domain will return the service's main front page, rather than the community site.

Configuration of the dotCommunity Service

An area (or sitewide) administrator has the ability to control the external domain setup for all websites within their responsibility. To configure a new external domain name select the Domain Names page under the Community Management tab, and click the Add Domain Name button.

The first part of the configuration involves selecting the community you wish to set up an external domain for. Browse for the website using the pagination controls at the top and bottom of the list and select it by clicking on its name.

After selecting the website you will be presented with a form field to enter the domain that will be configured to point to the dotCommunity service. Enter the domain, click OK and the site with its external domain will be added to the list.

Configuration of the External Domain

A dotCommunity service responds on the IP address that is returned for the main service domain name. For the purposes of explanation we will use an example service domain of dotcommunity.org with IP address 81.19.179.73 and an external owned domain of mysite.com.

When you want to point an external domain at a website on a dotCommunity service, you can do this in one of two ways:

1. Create an A record in the DNS for your domain for the service IP address, e.g. in the above example this would be 81.19.179.73. If the service can be accessed through more than one IP address these will each need to be added as separate A records. The A records can be set for the www subdomain as well as the basic domain e.g. www.mysite.com and mysite.com in our example, should both addresses want to be used to access the community site.
   A records have the advantage that they can sit alongside MX records - this means that in our example web requests for http://mysite.com can be sent to a different IP than emails to person@mysite.com.
   The disadvantage is that if the dotCommunity service has to change IP address for any reason (or adds further web servers, for example) then administrators using this method will need to update their DNS entries too.
2. Create a CNAME entry for www.mysite.com pointing to the service domain e.g. dotcommunity.org - a CNAME is an alias, so when a DNS lookup is done on mysite.com then it'll get the address for dotcommunity.org instead.
   The disadvantage of the CNAME is that, because it is an alias for the entire name, if you set the CNAME for mysite.com as well as www.mysite.com, then you cannot have a separate MX record for emails.

So, more concisely, if you want to use http://www.mysite.com/ then we recommend a CNAME. If you also want to use http://mysite.com/ then you'll have to use an A record, at least for the mysite.com part, unless you don't mind sacrificing the ability to use email on that domain.

Managing External Domains

To edit or remove an existing external domain configuration select the Domain Names page in the Commnity Management tab. To edit a domain mapping click the edit icon next to the community name. To delete a mapping click the delete button next to the domain.

dotCommunity checks the DNS of the configured domains to ensure that they are pointing to the correct IP address. It will not use any domain that is not configured correctly. Therefore it is perfectly safe to add a domain mapping to dotCommunity before you set up the DNS for that domain, and dotCommnity will start using it automatically as soon as you have configured it.

Each domain mapping has a status field to tell you if it is working. It can have one of three states:

• OK - the domain mapping is configured correctly, and dotCommunity will use it to access the community site.
• Lookup Failed - the DNS for the domain name has not been set up.
• Wrong IP - the DNS is set up, but is pointing to the wrong IP address. dotCommunity will not use it until the address is corrected.