Changing TTL for domin only affects domain.com but not www.domain.com

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1
SYSTEM INFORMATION
OS type and version Centos 7.9
Virtualmin version 7.10.0 Pro

Hi great people
A long time since i posted here.

I have a need to change the TTL of a domain ready for a move to another server (site is hosted elsewhere so I only need to update the “A” record) to 300 (5 minutes).
I have updated the TTL in the DNS settings > DNS Records > Manually Edit Records and saved.

The top line now reads “$ttl 300”.

When I check using online services I see that domain.com TTL is 300 but the www.domain.com is 11 hours.

Obviously I’m being thick as usual.

Please can someone point me in the right direction?

I know the OS is past it’s due date and as a result I cannot install the later version of Virtualmin. That is on my list of “to-dos”.

I would appreciate any help that anyone can offer.

2

If it was originally set to 11 hours, it can take up to 11 hours to update all records.

I don’t see a separate TTL for each A record in Virtualmin, compared to Cpanel where do have a TTL record, not sure why that is.

3

I just tried the command virtualmin modify-dns --domain example.com.au --all-ttl 5m
By the doc should add to all records, but doesn’t seem to add to the A records.

4

Am I correct to believe that www.domain.com is a sub-domain of domain.com?

If that is the case, should there be a different TTL anyway?

@staff can anyone there confirm this?

Thanks for your time everyone.

5

Yes, it is, and it can be just another record in the same zone as domain.tld or a separate zone record like www.domain.tld.

TTL is per record, not “per domain” or “per subdomain”.

6

@Ilia is the command as @stefan1959 has shown working as expected?

7

Yes, it worked perfectly fine for me:

root@debian12-pro:/var/lib/bind# virtualmin modify-dns --domain debian12-pro.virtualmin.dev --all-ttl 5m
Updating server debian12-pro.virtualmin.dev ..
    Setting default TTL to 5m ..
    .. done
.. done

root@debian12-pro:/var/lib/bind# gd
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   debian12-pro.virtualmin.dev.hosts

no changes added to commit (use "git add" and/or "git commit -a")
diff --git a/debian12-pro.virtualmin.dev.hosts b/debian12-pro.virtualmin.dev.hosts
index f57cc90..a84c1c6 100755
--- a/debian12-pro.virtualmin.dev.hosts
+++ b/debian12-pro.virtualmin.dev.hosts
@@ -1,6 +1,6 @@
-$ttl 3600
+$ttl 5m
 debian12-pro.virtualmin.dev.	IN	SOA	host.debian12-pro.virtualmin.dev. root.host.debian12-pro.virtualmin.dev. (
-			2025060500
+			2025111100
 			3600
 			600
 			1209600
root@debian12-pro:/var/lib/bind# systemctl restart named
root@debian12-pro:/var/lib/bind#
8

I thought that should add a TTL to all A records (and other records), like it is in CPanel

image
image837×384 22.9 KB

I can do it with the virtualmin modify-dns --domain example.com --add-record-with-ttl "www A 5m 192.0.2.1"
But thats adding a record not modifying a current record.

Thats how I read the docs, although I can see that the one setting would do all records though.

image

But then whats the difference between --ttl and --all-ttl flag

9

From the docs:

The default TTL for records can be set with the --ttl flag
followed by a number in seconds. Suffixes like h, m and d are also allowed
to specific a TTL in hours, minutes or days. Alternately, the --all-ttl
flag can be used to set the TTL for all records in the domain.

10

You probably shouldn’t do that in general. Unless you have a specific record that needs to change at a very different rate than the rest (e.g. some cloud thing with an ephemeral IP or whatever that you expect to change very frequently), it’s nicest to maintain one TTL.

1 Like
11

I’m happy asis, just testing and I don’t think the command does what it says in docs.
Might be useful for users who want to move say www to another server and just want the www A record to be a low TTL.
But getting off topic.

12

@stefan1959 Do the docs need new wording for this command.

Can you post here the doc URL and suggested changes to the wording? Or is it just in the cli?