I have a question about subdomain wildcards in Bind-style DNS editing, so that I can more conveniently edit DNS zone files to implement Fastmail's support of MX records specifying "*.mydomain.com." for e-mail at subdomains. (Yes, Fastmail's documentation states their support for this.)
Now, in Bind-style DNS, we have valid short notations for full FQDN in the name field (the left side) as follows:
"@" = "mydomain.com." "abc" = "abc.mydomain.com."
So my question is, might the following also be valid?
"*" = "*.mydomain.com." "*.@" = "*.mydomain.com."
Hartmut
On 2024-07-23 Hartmut W Sager wrote:
Now, in Bind-style DNS, we have valid short notations for full FQDN in the name field (the left side) as follows:
"@" = "mydomain.com." "abc" = "abc.mydomain.com."
So my question is, might the following also be valid?
"*" = "*.mydomain.com." "*.@" = "*.mydomain.com."
Yes, if your origin is still mydomain.com (which it should be), then * means *.mydomain.com.
Search "wildcard" in bind9 docs https://bind9.readthedocs.io/en/v9.18.13/chapter6.html
* IN MX 10 external1.example.com.
They use it in terms of a bastion host and internal views (probably not your situation). But the syntax would be valid regardless.
I'm not sure about *.@ so I'd just not use it.
My #1 word of advice is don't forget to increase your serial# by one each edit! LOL (I always forget)
My question for you(/others) is doesn't IN MX 5 example.com. in effect already mean: * IN MX 5 example.com. ???
I use wildcard MX in one of my domains
These lines are NOT equivalent: IN MX 5 example.com. * IN MX 5 example.com.
The latter will give you an MX record on host1.example.com but the former will say no MX record exists for host1.example.com
My server is PowerDNS not BIND so there's a chance that BIND would read this differently.
On 2024-07-24 01:32, Trevor Cordes wrote:
On 2024-07-23 Hartmut W Sager wrote:
Now, in Bind-style DNS, we have valid short notations for full FQDN in the name field (the left side) as follows:
"@" = "mydomain.com." "abc" = "abc.mydomain.com."
So my question is, might the following also be valid?
"*" = "*.mydomain.com." "*.@" = "*.mydomain.com."
Yes, if your origin is still mydomain.com (which it should be), then * means *.mydomain.com.
Search "wildcard" in bind9 docs https://bind9.readthedocs.io/en/v9.18.13/chapter6.html
- IN MX 10 external1.example.com.
They use it in terms of a bastion host and internal views (probably not your situation). But the syntax would be valid regardless.
I'm not sure about *.@ so I'd just not use it.
My #1 word of advice is don't forget to increase your serial# by one each edit! LOL (I always forget)
My question for you(/others) is doesn't IN MX 5 example.com. in effect already mean:
- IN MX 5 example.com.
??? _______________________________________________ Roundtable mailing list Roundtable@muug.ca https://muug.ca/mailman/listinfo/roundtable
-
Hartmut W Sager -
Scott Toderash -
Trevor Cordes