This document is for people who are getting a "dangling CNAME" warning, or who wish to have CNAME records that point to records served by other DNS servers.

There are two cases that can cause the "dangling CNAME" message to appear:

CNAMEs pointing to external host names

Sometimes, people may wish to have local names point to external entries with CNAME records. For example, it may be desirable to have the shortcut "google" for "". One way one may wish to do this is as follows: +86400 CNAME
MaraDNS' default configuration will not complete the record. In other words, some people may expect Mara to output the following for "": +86400 CNAME +900 A
Instead, Mara simply outputs: +86400 CNAME
I call this a "dangling CNAME record", since the CNAME record is not resolvable by some stub resolvers. In order to resolve dangling CNAME records, MaraDNS can be configured thusly: This will cause dangling CNAME records to be fully resolved; here is what the two MaraDNS servers do to resolve such a record:
  1. A stub resolver asks the IP address for, say ""
  2. asks the IP address for "" (since the name ends in "")
  3. tells " is a CNAME for, and I don't have an IP for it"
  4., seeing that it has a CNAME without an IP, asks nameservers on the internet for the IP for ""
  5. When has a complete record, it will send this record to the stub resolver. In other words, will tell the stub resolver that is a CNAME for, and then give out the IP for
Here is an example dwood3rc file for
ipv4_bind_addresses = ""
chroot_dir = "/etc/maradns"
recursive_acl = ""
upstream_servers = {}
upstream_servers[""] = ""
Here is an example mararc file for
ipv4_bind_addresses = ""
chroot_dir = "/etc/maradns"
csv2 = {}
csv2[""] = ""
If dangling CNAMEs are not an issue for a given setup, or if they are resolved by the above setup using both MaraDNS and Deadwood, the warnings about dangling CNAMEs can be turned off by adding this to a mararc file:
no_cname_warnings = 1

A typo can cause a dangling CNAME record

A typo can also cause a dangling CNAME record. E.g: CNAME A
Here, we mispelled the CNAME record; we meant to type "" but typed in "". We can also get a dangling CNAME thusly: CNAME A
Or by a typo in the mararc file:
csv2[""] = ""
(We typed in when we should have typed in "")

Followed by a zone file that looks like this: CNAME
host1.% A
Since the % will expand to "" instead of "".

In all of these cases, the dangling CNAME warning will go away when the typo is found and corrected.