topic Re: Problems with an _ in the DNS name with OnTap 9.3 in ONTAP Discussions

Problems with an _ in the DNS name with OnTap 9.3

Trubida — Wed, 04 Jun 2025 13:56:46 GMT

I have a AFF system running OnTap 9.3P1 and am seeing a strange issue. If we have a DNS entry for the cluster mgmt interface ,that contains an "_" character, I recieve the following error when trying to load the System Manager interface.

Bad Request
Your browser sent a request that this server could not understand.
Additionally, a 400 Bad Request error was encountered while trying to use an ErrorDocument to handle the request.

If I go to the IP address or a DNS entry that doesn't contain an _ I can logon as normal.

Is anyone else seeing this?

Re: Problems with an _ in the DNS name with OnTap 9.3

EWILTS_SAS — Thu, 08 Mar 2018 19:38:02 GMT

Underscores are not valid in DNS hostname entries.

The authoritative answer is in http://www.ietf.org/rfc/rfc952.txt

1. A "name" (Net, Host, Gateway, or Domain name) is a text string up
   to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
   sign (-), and period (.).

Re: Problems with an _ in the DNS name with OnTap 9.3

CSiegle — Fri, 23 Mar 2018 17:27:56 GMT

Trubida - Were you able to confirm this?

Re: Problems with an _ in the DNS name with OnTap 9.3

AlexDawson — Mon, 26 Mar 2018 06:09:46 GMT

Underscores are never ok in hostnames. Please change your DNS entries and it should all work fine.

Re: Problems with an _ in the DNS name with OnTap 9.3

zamkovoy8 — Mon, 09 Apr 2018 22:58:23 GMT

https://mysupport.netapp.com/NOW/cgi-bin/bugrellist?bugno=1139424

agree, it was never a good idea.. i guess that escaped NetApp guys not just once .. ONTAP Cloud default SVM name is created using svm_ prefix .. even today.