GTM Server name is unknown

[Amr_Ali]

Hello, 

I configured A record on our GTM, but after using the nslookup tool on CLI to check the IP if The URL I find that the server name is unknown as in the below screenshot, I just ask is normal to be unknown

[AubreyKingF5]

It's been a bit, but I think that happens when you do not have a PTR for your. NS. dig -t NS against the zone, also?

[Amr_Ali]

how can I solve this, is there any article or link 

[Paulius]

@Amr_Ali For a PTR I believe you can configure that on the authoritative name server that particular PTR. I believe the NS issue would also be configured at the authoritative name server for that zone or sub-domain.

[AubreyKingF5]

Yes. The authoritatve server would need to have that, so, depending on your authoritatve resource, could be a number of different ways to do that, but really.. I think that is the issue.