Using wildcard does not resolve sub of subdomain

Question

I have a domain xyz.com on (xx.xxx.255.25) and sub.xyz.com on (xx.xxx.255.240)
To resolve sub I added the following reocrd in BIND

sub IN A xx.xxx.255.240
*.sub IN A xx.xxx.255.240

and worked well, but the problem is with the sub of subdomain it did not resolve.
I tried adding a test sub and worked well:

test.sub IN A xx.xxx.255.240

The point of the wildcard (*) is that I have multiple subs (FTP, mail, SMTP...)
So where exactly I did wrong caused the sub of the subdomain to not resolve?

[UPDATE]

Resolving sub of subdomains worked as *@Tommiie* said, but the second problem appeared is with `TXT` records (SPF, DKIM, DMARC), Can I add wildacrd as `A records` to resolve them?

Normally bind is configured to allow shorthand and unqualified resource records (those whose name does not end in a `.` dot) get appended with the zone name. A record `host` in the `example.com.` zone file will have the name of the zone appended and be processed as `host.example.com.` Your question mentions record `sub.` with a trailing dot. Those are FQDN’s and won’t have the zone name appended. — Bob, Nov 25 '20 at 13:05
even after removing the dot at the end I still have the same issue. — Ahmad, Nov 25 '20 at 13:08

Tommiie · Accepted Answer · 2020-12-04T15:21:15.237

3

Do you have other records in the sub subdomain?

The wildcard character matches any number of labels in a name as long as there isn't an exact match with a name already in the name server's database.

Quote from DNS & BIND (5th edition), p. 488

As you also want TXT wildcard records:

*.sub.example.com.  A     xx.xxx.255.240
*.sub.example.com.  TXT   "spv record"
*.sub.example.com.  TXT   "dkim record"
*.sub.example.com.  TXT   "more text records"

Please share a more complete configuration.

PS: remove the trailing dots. It wont work with them in place.

edited Dec 04 '20 at 15:21

answered Nov 30 '20 at 16:09

Tommiie

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In the server **xx.xxx.255.240** where `sub` is, there are different records but why it matters? – Ahmad Nov 30 '20 at 20:08
If you have ``test.sub..`` then ``*.sub.`` will never hit. – Tommiie Dec 01 '20 at 11:16
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so I need to delete `test` and it must work well, right? but what about **TXT** records? – Ahmad Dec 01 '20 at 17:55
Since you create a wildcard for an A record, it only goes for A records. TXT records can remain in the database. – Tommiie Dec 01 '20 at 19:58
@AragonS: if your issue fixed? Or is it still not working? – Tommiie Dec 03 '20 at 13:34
for `A records` it worked but I am trying to add `SPF, DMARC, DKIM`, but **TXT records** do not resolve – Ahmad Dec 04 '20 at 14:53
Please update your question with your current configuration. – Tommiie Dec 04 '20 at 15:02
just update it! – Ahmad Dec 04 '20 at 15:12
Add a wildcard TXT record similar to the wildcard A record. – Tommiie Dec 04 '20 at 15:14
so it should be `*.sub. IN TXT xx.xxx.255.240`, right? – Ahmad Dec 04 '20 at 15:18
Updated the answer. – Tommiie Dec 04 '20 at 15:21
Just to be sure, by "SPF record" you mean just a quote or the actual record? – Ahmad Dec 04 '20 at 15:26
no... you enter your SPF record there. – Tommiie Dec 04 '20 at 15:27

Using wildcard does not resolve sub of subdomain

[UPDATE]

1 Answers1