underscore in A or PTR records

Matus UHLAR - fantomas uhlar at fantomas.sk
Wed Feb 17 08:53:17 UTC 2021

On 17.02.21 08:13, ONRUBIA AVILES Carlos (CCS/MST) wrote:
>I face the following problem  ==> bind do not accept an A record with underscore:
>Example:     example_try   A
>Same for a PTR:
>Example:   PTR   example_try
>Is it absolutely forbidden to have in such cases an '_'?

absolutely no, but since underscore is not valid in hostname as per rfc1123,
I don't recomment you to use it in hostnamed.

>I know that it is possible for SRV or TXT records.

it's valid in DNS, but not in hostnames.  You can in fact disable checking
but you may encounter problems with remote sites.

Matus UHLAR - fantomas, uhlar at fantomas.sk ; http://www.fantomas.sk/
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