Extraneous DNS queries from Xymon
I have defined some hosts with fake host names: 0.0.0.0 foo.bar.foo # noconn They are defined so that clients may send messages to the Xymon server and have their status displayed.
What I don't understand is why my Xymon server insists on performing name queries for foo.bar.foo. Even adding "testip" to the line doesn't eliminate all of the queries. The only way I can make them stop is by making bogus entries in my server's hosts file, of the form: 127.0.0.2 foo.bar.foo
There are no xymonnet tests defined for this host. The server is not running xymond_alert or xymongen.
What component is querying DNS, and why?
Do things because you should, not just because you can.John Thurston 907-465-8591 John.Thurston at alaska.gov Enterprise Technology Services Department of Administration State of Alaska
Am 06.01.2016 um 19:38 schrieb John Thurston:
I have defined some hosts with fake host names: 0.0.0.0 foo.bar.foo # noconn They are defined so that clients may send messages to the Xymon server and have their status displayed.
What I don't understand is why my Xymon server insists on performing name queries for foo.bar.foo. Even adding "testip" to the line doesn't eliminate all of the queries. The only way I can make them stop is by making bogus entries in my server's hosts file, of the form: 127.0.0.2 foo.bar.foo
There are no xymonnet tests defined for this host. The server is not running xymond_alert or xymongen.
What component is querying DNS, and why?
try add
https://www.xymon.com/help/manpages/man5/hosts.cfg.5.html
testip and noconn
Best Regards MfG Robert Schetterer
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On 1/6/2016 9:54 AM, Robert Schetterer wrote:
Am 06.01.2016 um 19:38 schrieb John Thurston:
I have defined some hosts with fake host names: 0.0.0.0 foo.bar.foo # noconn
- snip - Even adding "testip" to the line doesn't eliminate all of the queries.
try add https://www.xymon.com/help/manpages/man5/hosts.cfg.5.html testip and noconn
As stated in my original message, 'noconn' is already specified for the host. Adding 'testip' reduces the number of queries but does not eliminate them.
I forgot to mention: xymon version 4.3.17 running on CentOS
-- Do things because you should, not just because you can.
John Thurston 907-465-8591 John.Thurston at alaska.gov Enterprise Technology Services Department of Administration State of Alaska
Hmm. "noconn" + "testip" should actually be all that's needed here, assuming there are no other references to those (in URLs, for example). I've used a lot of pseudo-DNS entries in configs before for the same effect.
Can you run a copy of xymonnet in --debug mode and see if you see the lookup there? If nothing, then an strace should reveal around when we're doing it.
Have you noticed any patterns in *which* hosts you're seeing the lookup for that you're not expecting it at? Or is it all of them?
-jc
On Wed, January 6, 2016 11:04 am, John Thurston wrote:
On 1/6/2016 9:54 AM, Robert Schetterer wrote:
Am 06.01.2016 um 19:38 schrieb John Thurston:
I have defined some hosts with fake host names: 0.0.0.0 foo.bar.foo # noconn
- snip - Even adding "testip" to the line doesn't eliminate all of the queries.
try add https://www.xymon.com/help/manpages/man5/hosts.cfg.5.html testip and noconn
As stated in my original message, 'noconn' is already specified for the host. Adding 'testip' reduces the number of queries but does not eliminate them.
I forgot to mention: xymon version 4.3.17 running on CentOS
-- Do things because you should, not just because you can.
John Thurston 907-465-8591 John.Thurston at alaska.gov Enterprise Technology Services Department of Administration State of Alaska
Xymon mailing list Xymon at xymon.com http://lists.xymon.com/mailman/listinfo/xymon
On 1/6/2016 1:11 PM, J.C. Cleaver wrote:
Hmm. "noconn" + "testip" should actually be all that's needed here,
Well, I must apologize to everyone for the noise.
It is now behaving exactly as you indicate. I must assume my previous tests with these tags were somehow invalid. Maybe I wasn't editing the right file. Maybe I was misspelling 'testip'.
I am able to get adequate behavior by inserting a .default. line containing 'testip noconn' above my collection of fake names.
xymonnet must be building its table of host name/address pairs before it looks to see if there are any tests to be run. This isn't terribly efficient, but obviously not a big deal in the grand scheme of things.
Do things because you should, not just because you can.John Thurston 907-465-8591 John.Thurston at alaska.gov Enterprise Technology Services Department of Administration State of Alaska
participants (3)
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cleaver＠terabithia.org
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john.thurston＠alaska.gov
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rs＠sys4.de