Can I change my DNS entries?
You can use the account management control panel to add, manage and delete custom DNS entries. For example, you could add a new record that points "home.example.com" at your home computer, or you could override the standard MX records we provide.
DNS is a complicated subject. Although our control panel makes it easy to make changes, you should be familiar with how DNS works to know whether a change is appropriate. Altering DNS entries can cause problems with Web or e-mail services we provide for you. If you have any questions, please contact us before making any changes; we’ll be happy to help and give advice.
On this page:
- Editing DNS settings
- What is the "DNS zone file" shown on the DNS editing page?
- How do I override default DNS entries?
- Do you provide "reverse DNS" pointer records?
- Do you provide secondary backup MX service?
- Using Microsoft Exchange Server
- I see a default "TXT" record for my Web hosting account. What is that?
- Can I add my own SPF or DKIM entries?
- Do you provide dynamic DNS service?
- Can you explain how DNS works?
Editing DNS settings
To edit and view your DNS settings:
- Login to the control panel
- If your account is a Web hosting account, click Domain Name Options (this step is not necessary if you don’t have Web hosting service with us)
- Click Edit DNS Zone
You’ll be able to easily add and alter the DNS records for your Web site.
What is the "DNS zone file" shown on the DNS editing page?
Although we provide a convenient, understandable interface for making DNS changes, the way that DNS servers really work behind the scenes is to read the DNS entries in a special format from a "DNS zone file". Because some advanced DNS users are familiar with the format of the zone file, we display a copy of the file for experts to examine. What you see is the same zone file that our DNS servers actually use.
If you aren’t familiar with the zone file, you should simply ignore the "DNS zone file" section of the control panel.
How do I override default DNS entries?
We provide several DNS records by default:
- “example.com”, “www.example.com” and all unknown subdomains (“*.example.com”) are “A records” that point to the IP address of your Web site on our servers. (The wildcarding of subdomains makes Web site subdomains work.)
- We add “ftp.example.com” as a CNAME record for “ftp.tigertech.net”.
- We add MX records for incoming mail, A records for “lists.example.com” and “www.lists.example.com” to make Mailman lists work, a TXT record for SPF (see below for more about SPF), and an “autodiscover” CNAME record for Outlook autodiscovery.
- If your account was established before June 13, 2008, we also include CNAME records for “pop.example.com” and “smtp.example.com” for compatibility reasons (we don’t support using those hostnames for newer accounts).
You can override any of these by simply adding a new record of the same label and type. For example, if you add a new A record or CNAME record for ftp.example.com, our default “ftp.example.com” record will not be used.
In addition, none of the mail-related records will be used if you add any MX record for example.com.
You can override the “wildcard” by adding a new record for *.example.com.
If you want to completely suppress a record that appears in our zone file by default, you can use the special A record target none. For example, adding an A record pointing *.example.com to none will make all requests for unknown hostnames return NXDOMAIN (which would prevent Web subdomains from working unless you manually re-add each subdomain you want to use).
If you suppress wildcards but you then want to add DNS entries for certain hostnames, you can use the special target default for a new A record, and that IP address will always point at the correct IP address for your site on our servers. Finally, although there’s no way to leave the wildcard entry in place and suppress a single subdomain, some people who want to make sure that a single subdomain hostname doesn’t reach our servers add an A record pointing that hostname at reserved address space such as 192.0.2.1, which is guaranteed never to exist on the real Internet.
Do you provide "reverse DNS" pointer records?
We’re often asked this question when customers add an A record that points to the IP address of their home DSL or cable modem connection. However, the company that owns an IP address (not the company that runs the domain name) is the company that provides reverse DNS entries.
For example, if you add "office.example.com" as a DNS entry pointing to your business Comcast cable IP address at 192.0.2.34, only Comcast can set up reverse DNS entries that would map 192.0.2.34 back to "office.example.com" — we can’t do that.
For reverse DNS entries, you should contact the company that issued you the IP address (probably your ISP — the company that provides your modem connection).
Do you provide secondary backup MX service?
We don’t provide secondary MX service or MX forwarding. If you’re setting up your own mail servers to receive incoming mail, you should list only those servers in the MX records. You should never include our MX servers in addition to your own. (When you add a new DNS MX entry, our standard MX servers will automatically be overridden for your domain name and all mail will arrive directly at the MX server you enter.)
There are several reasons we don’t offer backup MX service, but the main one is that it causes far more problems than it solves on today’s Internet. We’d usually have no way of knowing what usernames are valid on the primary server, so our servers would have to accept mail for any address at your domain name. A huge percentage of that mail would be spam (spammers intentionally try delivering to secondary MX servers because they tend to have more permissive spam filters). Delivering that amount of spam to you or bouncing it (probably to forged sender addresses, called "backscatter") would both lead to major problems.
There should be no need for third-party backup MX servers at all with modern networks. Even if your primary mail server is down for some time, sending servers are required by Internet standards to queue mail and keep retrying all deliveries for at least four days, so you should never lose any mail. As long as your primary mail server starts working within four days, the mail will be delivered to you.
(Although we don’t provide secondary MX service, we do allow you to use another MX server for the initial delivery/filtering/archiving/etc., then have the other server deliver mail to our incoming MX servers so you can read it here. The other server should be manually configured to redeliver the mail to mx.tigertech.net, although you shouldn’t include that name in your MX records. Note that because our servers can no longer see the IP address of the sender’s mail server, doing this markedly lowers the effectiveness of our spam filters.)
Using Microsoft Exchange Server
You can add custom MX records as described above if you are running your own mail server such as Microsoft Exchange.
If you’re using a Microsoft Exchange server and you’re concerned about reliability, you may want to consider using the "Exchange Connector for POP3 Mailboxes", as described in the "LAN with Multiple POP3 Accounts" section of this page. This allows you to use Exchange even if your mail server is unavailable for more than four days or you have a dynamic IP address.
I see a default "TXT" record for my Web hosting account. What is that?
The TXT record we include by default is an SPF record. When you send mail to other ISPs that use the SPF anti-spam system, the receiving server uses the TXT record to verify that our servers are legitimate senders of mail for your domain name. This makes the messages less likely to be incorrectly rejected by spam systems.
The default TXT record will not be included in your DNS entries if you add any custom MX or TXT records for your domain name.
Can I add my own SPF or DKIM entries?
If you use our e-mail service, we automatically set up valid SPF records for your domain name. You don’t need to do it yourself.
You can enter these as normal TXT records using our control panel. (You can enter TXT records without or without the surrounding quote marks that DNS requires; if your TXT data contains spaces and you omit the quotes, we’ll add them to the zone file automatically.)
Do you provide dynamic DNS service?
"Dynamic DNS" services allow you "point" custom DNS hostnames at your home computer, even if your home IP address changes frequently. By using a free dynamic DNS service and adding a custom DNS entry for example.com, you can easily point hostnames like "home.example.com" at a dynamic IP address, such as your home DSL or cable modem connection.
Once you have that hostname, use your example.com control panel to add a "CNAME" DNS entry for "home.example.com" that has the dynamic DNS hostname as the "CNAME target". After doing this, you’ll be able to connect to your IP address using "home.example.com" as well as "example.dyndns.org": the two hostnames will be interchangeable for most purposes.
Although we’ve used "home.example.com" as an example here, you can use any hostname that doesn’t interfere with another service we offer. For example, you could add a CNAME record for "office.example.com" or "private.example.com". The only thing to keep in mind is to make the CNAME target be the dynamic hostname that the other company provided to you.
Can you explain how DNS works?
DNS is a complex subject that literally has entire books written about it; explaining how it works is more than we can do here, unfortunately. A useful introduction is the Wikipedia article on DNS, and a search for "DNS tutorial" in your favorite search engine will provide plenty of links.