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How to add a Certification Authority Authorization (CAA) record in NSD 4.1.7

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Requirements :

  • NSD from NLnet Labs
  • Linux/Windows OS with NSD installed (in this example using Linux Ubuntu version 16.04 LTS)
  • Functional DNS Server

There is a video for this solution.

Here is the process:

1. Login to your DNS server.

2. Launch the Terminal. If you don’t login as superuser, use the sudo command:

$ sudo –i

You will be prompted for your superuser password. Type the password and you will be on the root prompt.

3. Check your version of NSD. This is mandatory to determine which entry is applicable for your BIND version.

Standard CAA Zone File for  NSD version 4.0 and higher       CAA       0 issue ""
Legacy CAA Zone File for NSD version lower than 4.0        TYPE257 \# 18 00056973737565656E74727573742E6E6574

To check the NSD version, use the command below:

Root# nsd -v

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4. Locate your DNS zone file by using the command below:

ls - l <DNS zone file location>

This file by default is located under /etc/nsd/ , however the file may be hidden for security reasons. Please consult with your network administrator if you do not find the file in its default folder.

In this example, the DNS zone file is under /etc/nsd/ with the filename called

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WARNING ! Before you continue on the step below, please make sure you make a copy of your working DNS zone file to avoid any missteps.

Tip: To copy the file use the command cp <DNS zone file location/DNS zone file name>

5. Edit the zone file using a line text editor tool such as nano or vi.

For example:

#root: nano /etc/nsd/

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The DNS zone file will open:

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6. Scroll to the bottom of your zone file and hit Enter to create a new  line for your new record entry.

7. Copy/Paste or type the entry below to the empty line space:

yourdomain_name.IN       CAA       0 issue ""

Note: There are seven spaces between each of the first three character sets.

Also Note: To add a different Certification Authority as the Authorized CA, please add the entry related to that Certification Authority.

8. Press Ctrl-X to save the modification. Answer Yes and then hit Enter to overwrite the changes to your zone file.

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9. Restart your DNS service by typing:

Root # service <named> restart

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NOTE: If you receive any errors during the DNS service restart process, go back to your zone file and make sure you don’t have any typos in your zone file. You can still refer back to your old working zone file that you backed-up in step 4.

9. To check the detail status of DNS service, type :

Root# service <named> status

To check if the CAA record has been updated correctly and can be queried, use the command:

Root # dig type257

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The above shows a CAA Record for Entrust that has been successfully added. (See ANSWER section).

If you have any questions or concerns please contact the Entrust Certificate Services Support department for further assistance:

Hours of Operation:
Sunday 8:00 PM ET to Friday 8:00 PM ET
North America (toll free): 1-866-267-9297
Outside North America: 1-613-270-2680 (or see the list below)
NOTE: Smart Phone users may use 1-800 numbers for one-touch dialing.
Otherwise, it is very important that international callers dial the UITF format exactly as indicated. Do not dial an extra "1" before the "800" or your call will not be accepted as an UITF toll free call.

Country Number
Australia 0011 - 800-3687-7863
Austria 00 - 800-3687-7863
Belgium 00 - 800-3687-7863
Denmark 00 - 800-3687-7863
Finland 990 - 800-3687-7863 (Telecom Finland)
00 - 800-3687-7863 (Finnet)
France 00 - 800-3687-7863
Germany 00 - 800-3687-7863
Hong Kong 001 - 800-3687-7863 (Voice)
002 - 800-3687-7863 (Fax)
Ireland 00 - 800-3687-7863
Israel 014 - 800-3687-7863
Italy 00 - 800-3687-7863
Japan 001 - 800-3687-7863 (KDD)
004 - 800-3687-7863 (ITJ)
0061 - 800-3687-7863 (IDC)
Korea 001 - 800-3687-7863 (Korea Telecom)
002 - 800-3687-7863 (Dacom)
Malaysia 00 - 800-3687-7863
Netherlands 00 - 800-3687-7863
New Zealand 00 - 800-3687-7863
Norway 00 - 800-3687-7863
Singapore 001 - 800-3687-7863
Spain 00 - 800-3687-7863
Sweden 00 - 800-3687-7863 (Telia)
00 - 800-3687-7863 (Tele2)
Switzerland 00 - 800-3687-7863
Taiwan 00 - 800-3687-7863
United Kingdom 00 - 800-3687-7863
0800 121 6078
+44 (0) 118 953 3088