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How to add a CAA record into a DNS zone file using BIND DNS

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There is a video for this solution.

Requirements :

  • BIND DNS Software from ISC
  • Linux/Windows OS with BIND installed (in this example using Linux CentOS version 7)
  • DNS Server has been setup and function properly

Steps to setup:

1. Login to your DNS server using superuser as root.

2. Launch the terminal. If you don’t login as superuser then type: $ sudo –

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

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

Standard BIND Zone File for BIND version 9.9.6 and higher       CAA       0 issue ""
Legacy BIND Zone File for BIND version below 9.9.6        TYPE257 \# 18 00056973737565656E74727573742E6E6574

To check the Bind version type, use the command below :

named -v

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4. Locate your DNS zone file. This file by default is located under /var/named/ , however sometimes it is hidden for the security purposes. Please consult with your network administrator. In this example, the DNS zone file is under /var/named/ with the filename called

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

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


nano /var/named/

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The DNS zone file will be opened. You should see the current, already existing entry:

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6. Hit Enter at the end of the line with $TTL 86400 to give a line space below for new record entry.

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7. Copy and paste the entry below to the empty line space that created from step 6 above.

@   IN          TYPE257 \# 18 00056973737565656E74727573742E6E6574

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NOTE: If your DNS zone file is empty, then you need to type the entry starting from $ORIGIN with your own FQDN domain name.

8. Press Ctrl-X to save the modification. Answer Yes and then hit Enter to overwrite it into the same filename.

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9. Restart your DNS service by typing:

service named restart

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NOTE: If you receive any error during the DNS service restart process, go back to your zone file and make sure you don’t have any typo on the entries. You can still refer back to your old working zone file that you backup on step 5.

To check the detail status of DNS service, type :

service named status

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10. To check if the CAA record has been updated correctly and can be queried, you can run the command:

Root # dig <yourdomainname> type257

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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: 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