Warning: "The installation was unable to look up DNS names for the following servers:<Server DNS Name containing underscores>"

  • 3696458
  • 04-Feb-2008
  • 30-Apr-2013


Novell ZENworks for Servers 3.0
Novell Cluster Services (NCS).


Warning: "The installation was unable to look up DNS names for the following servers:"
Warning: "Without DNS configured correctly in your network, TED may not function. Would you like to continue the installation to these servers anyway?"
The Servers DNS has the "_" underscore character due to the default naming of NCS.
Ping -a returns the DNS name containing the "_" underscore character.
Due to the installation process determining the DNS Name has the"_" underscore character the product will not use the DNS name but the IP Address instead.


1.Change the DNS entry and remove the "_" underscore character.
2. Continue the installation without DNS resolution and allow the IP Address the be used instead.
Another reason this might happen is if your C:\WINDOWS\SYSTEM32\DRIVERS\ETC\HOSTS file has an entry with ONLY a short name of your server like this " server1". Change it to " server1.novell.com server1" and then you have to RESTART the ZFS install after changing that.

Additional Information

DNS names do not support the underscore character "_", refer to RFC 952
The installation process detects the "_" underscore character in the DNS name and therefore displays the warning message.
1. The ZFS processes will give a warning message when loading because DNS is not being used.
2. If the Server's IP Address changes the ZFS product would need to be re-installed.
The fully distinguished computer name of the Windows Server needs to match the DNS name. If the Server is a member of an Active Directory Domain then the computer name is used by ZFS.
1. BIND and DNS standards, RFC 1912 states which characters and character orders are acceptable. Section 2.1 Paragraph 4 of RFC 1912:
"Allowable characters in a label for a host name are only ASCII letters, digits, and the `-' character. Labels may not be all numbers, but may have a leading digit (e.g., 3com.com). Labels must end and begin only with a letter or digit. See [RFC 1035] and [RFC 1123]. (Labels were initially restricted in [RFC 1035] to start with a letter, and some older hosts still reportedly have problems with the relaxation in [RFC 1123].) Note there are some Internet hostnames which violate this rule (411.org, 1776.com). The presence of underscores in a label is allowed in [RFC 1033], except [RFC 1033] is informational only and was not defining a standard. There is at least one popular TCP/IP implementation which currently refuses to talk to hosts named with underscores in them. It must be noted that the language in [1035] is such that these rules are voluntary – they are there for those who wish to minimize problems. Note that the rules for Internet host names also apply to hosts and addresses used in SMTP (See RFC 821).”
Netware will support FQDN’s with underscores ONLY if the IP to FQDN resolution is listed in the …/etc/hosts file. Reverse resolution does not occur correctly unless the IP and it’s corresponding FQDN are listed in …/etc/hosts file. This is a problem in two scenarios:
· If you have a NATed (Network Address Translation) environment, a recipient may or may not be able to reply depending on the routes back to the sender, as internet routers will drop packets, whose destination are 10.x.x.x, 172.16.x.x or 192.168.x.x.
· When inserting the –hosts switch (required for multi homed machines) in the TED ncf file, all hostnames and/or IP addresses resolving to an FQDN with underscores MUST be listed in the …/etc/hosts file.

Formerly known as TID# 10074879