Hello,
On windows , its combination of how your TCP IP settings are setup and 
name resolution is configured, on networker side, i believe if the clients 
are created with FQDN then host file is consulted first, if they are short 
name clients, DNS  first.
Don't forget about alias settings within a client ( add all known aliases 
of the client), if DNS returns a different client name  if any C-Names 
have been configured for a host, the backups can fail also. You will need 
to educate the Windows admins to notify you if and when any new names are 
configured for a given host.
HTH




"Goslin, Paul" <pgoslin AT CINCOM DOT COM> 
Sent by: EMC NetWorker discussion <NETWORKER AT LISTSERV.TEMPLE DOT EDU>
10/06/2008 10:24 AM
Please respond to
EMC NetWorker discussion <NETWORKER AT LISTSERV.TEMPLE DOT EDU>; Please respond 
to
"Goslin, Paul" <pgoslin AT CINCOM DOT COM>


To
NETWORKER AT LISTSERV.TEMPLE DOT EDU
cc

Subject
Re: ALL Clients suddenly started failing






 That may be very well what we have to do....

I opened a ticket with our DNS keepers, and they've responded that they 
see no problems over the weekend with DNS... That does not explain why 90% 
of our backups failed with DNS related errors... How should I respond to 
people who are asking 'why did our backups fail ??'  I can't provide a 
reason other than apparent DNS issues... Which if it was really a DNS 
problem, other things besides backups would have had problems also, but 
nothing else did... To me, it's a Networker problem... I hate it when 
Networker backups fail and you can't tell why after the fact... 

Is there anything special that has to be done to make networker use a 
combination of a local hosts file plus DNS ??


> -----Original Message-----
> From: EMC NetWorker discussion 
> [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of Coty, Edward
> Sent: Monday, October 06, 2008 11:16 AM
> To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
> Subject: Re: [Networker] ALL Clients suddenly started failing
> 
> How about using local hosts files and then DNS. This way if 
> you miss something with updating your local host files then 
> hopefully DNS will pick it up. We use DNS primarily here but 
> in a DR situation we have relied on local host files and not 
> DNS. You can maintain both so you have some redundancy in 
> your name resolution.
> 
> 
> EDWARD COTY
> 
> LEAD STORAGE ENGINEER, LCNA, NACP
> 
> WORK - 973-533-2098
> 
> CELL - 973-296-0918
> 
> EDWARD.COTY AT AIG DOT COM
> 
> 
> -----Original Message-----
> From: EMC NetWorker discussion 
> [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of Davina Treiber
> Sent: Monday, October 06, 2008 10:40 AM
> To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
> Subject: Re: [Networker] ALL Clients suddenly started failing
> 
> Goslin, Paul wrote:
> > While I agree that maintaining a client host file is a 
> PITA.... It's not that much effort in my experience... And 
> worth it in the long run. Unless you have a very dynamic 
> network with backup clients constantly being added / removed....
> 
> If you believe that then you are perfectly at liberty to 
> convert your environment to use hosts files. However from my 
> experience it will be a nightmare. As an example consider the 
> case when you decide to add a new storage node and you have 
> to add that address to the hosts file on 600 clients. I would 
> not want to be the one tasked with that. OK perhaps your 
> environment is not that large, but that just illustrates the 
> fact that hosts files do not scale and DNS does.
> 
> >
> > I feel it's more practical than naïve... I now have a 
> weekend of failed backups due to failed DNS lookups... I have 
> no control over the DNS server...  As long as the client is 
> up and responding on the proper ports, Networker should 
> simply back it up.... What does it matter if the reverse 
> lookup fails, and how is that more significant than backing 
> up your companies' data ???
> >
> 
> The point of the reverse lookup is to verify to each machine 
> that the other machines are what they say they are. Not 
> everyone agrees that this is the best security method, but 
> you have other options for this now anyway.
> 
> What else in your network stopped working when DNS went down? 
> In most organisations this would generate a call-out and 
> someone would be fixing it toute-suite.
> 
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