Hello,
I am demoing out the NAV appliance and we have a number of physical and virtual hosts that do not have reverse DNS entries available, resolution of the IPs belonging to the hosts results in unknown.domainname.tld.
When attempting to add multiple hosts to the NAV seed database, I receive errors when NAV attempts to resolve the DNS name of the host, claiming that the host already exists, despite all unique information with the exception of the failed resolution of the fqdn.
Is there a work-around so that NAV does not lookup the DNS name of said devices?
Sincerely,
Jesse
Hello,
I am demoing out the NAV appliance and we have a number of physical and virtual hosts that do not have reverse DNS entries available, resolution of the IPs belonging to the hosts results in unknown.domainname.tld.
When attempting to add multiple hosts to the NAV seed database, I receive errors when NAV attempts to resolve the DNS name of the host, claiming that the host already exists, despite all unique information with the exception of the failed resolution of the fqdn.
Is there a work-around so that NAV does not lookup the DNS name of said devices?
Maybe a list in /etc/hosts could work?
You know, that's an excellent idea.
I will compile a short list of hosts to test with and let you know the outcome.
Sincerely,
Jesse
-----Original Message----- From: nav-users-request@uninett.no [mailto:nav-users-request@uninett.no] On Behalf Of Jan Sigurd Refvik Sent: Friday, August 8, 2014 12:14 AM To: 'jorr@streamguys.com'; nav-users@uninett.no Subject: RE: Sysname () is already in database
Hello,
I am demoing out the NAV appliance and we have a number of physical and virtual hosts that do not have reverse DNS entries available, resolution of the IPs belonging to the hosts results in
unknown.domainname.tld.
When attempting to add multiple hosts to the NAV seed database, I receive errors when NAV attempts to resolve the DNS name of the host, claiming that the host already exists, despite all unique information with the exception of the failed resolution of the fqdn.
Is there a work-around so that NAV does not lookup the DNS name of said devices?
Maybe a list in /etc/hosts could work?
On Fri, 8 Aug 2014 07:13:57 +0000 Jan Sigurd Refvik j.s.refvik@usit.uio.no wrote:
Is there a work-around so that NAV does not lookup the DNS name of said devices?
Maybe a list in /etc/hosts could work?
Yes, and no, I'm afraid. While SeedDB uses the standard system resolver, ipdevpoll us built using the Twisted framework, which features its own DNS resolver code. ipdevpoll will talk directly to the resolvers listed in /etc/resolv.conf. So you might fool SeedDB, but not ipdevpoll.
There may be ways to have the Twisted names framework use both, though I haven't looked into it.
On Thu, 7 Aug 2014 23:58:12 +0200 (CEST) jorr@streamguys.com wrote:
I am demoing out the NAV appliance and we have a number of physical and virtual hosts that do not have reverse DNS entries available, resolution of the IPs belonging to the hosts results in unknown.domainname.tld.
It sounds like your DNS server is responding to queries for non-existant PTR records with a default name of "unknown.domainname.tld", instead of properly responding with an error.
I'm no DNS expert, but I fail to see how that is a sound strategy, if that is the case.
When attempting to add multiple hosts to the NAV seed database, I receive errors when NAV attempts to resolve the DNS name of the host, claiming that the host already exists, despite all unique information with the exception of the failed resolution of the fqdn.
If the DNS server is indeed not responding with failure, but returning the same hostname for all unknown addresses, then yes, you will have problems.
NAV is perfectly fine with a failed DNS lookup; It will keep the host's IP address as its system name.
Is there a work-around so that NAV does not lookup the DNS name of said devices?
No and yes. SeedDB will look up names as you enter single IP devices. IIRC, it leaves that job to ipdevpoll if you bulk import a bunch of devices. ipdevpoll will also regularly check for DNS names and changes to those. This lookup can, however, be disabled, by removing the dnsname plugin from any job configurations it is present in (ipdevpoll.conf).
I would still have a look at your DNS policy, though...
-
Jan Sigurd Refvik -
jorr＠streamguys.com -
Morten Brekkevold