Linux client and Windows DNS

[OTEN Helpdesk]

Hi,

We have a W2K3 DNS in our network. We also have a number of RHEL linux servers installed and points to the W2K3 DNS as its primary DNS/name server.

The W2K3 DNS is a DC and has the directory-integrated windows domain zone. In addition, the DNS server also has a secondary zone configured for 'company.net.edu.au'. All our linux servers are entered into this zone as Host entries.

We have a windows netbackup server backing up windows and linux servers. The problem is, when our WAN goes down, backup fails for all the linux servers. Backup of Windows servers are fine. Logs show that netbackup server and linux servers couldn't resolve each (ex. linuxserver.company.net.edu.au)

The master server for the secondary zone is located across the WAN. However, netbackup server and all windows and linux servers are located in the same LAN/subnet.

I have a feeling that the Linux servers are unable to resolve using the secondary zone configured in the W2K3 DNS server. But why are they working fine when the WAN is up?

Cheers,
Cris

[Steven Schweda]

What are the Linux systems using as DNS
servers?

grep nameserver /etc/resolv.conf

And where are they?

Same for the netbackup server?

> Logs show [...]

They might show you, but I can't see a thing.
Who can't resolve whom (by name or by
address)?

> However, netbackup server and all windows
> and linux servers are located in the same
> LAN/subnet.

It's nice that they're close, but if they
can't get each other's addresses, they won't
know how close they are.

[Ivan Ferreira]

>>> Logs show that netbackup server and linux servers couldn't resolve each (ex. linuxserver.company.net.edu.au)

So, the netbackup server can't resolve a Linux host. Are you sure that your Windows DNS server is answering queries for the secondary zone? Have you tested with:

dig @windows-dc.domain.dom some.linux.host.

>> The master server for the secondary zone is located across the WAN. However, netbackup server and all windows and linux servers are located in the same LAN/subnet.

>> But why are they working fine when the WAN is up?

If the WAN is up, then you will be able to contact the primary DNS server for that domain. Do you have forwarders configured in your Windows DNS domain for company.net.edu.au ?? If so, then you should remove it, as you already hold a secondary zone.