On Tue, 2019-03-12 at 13:57 +0000, SebA wrote:
I don't really understand why you would be negating the dns test on the server, rather than just removing it altogether. You will be slowing down xymonnet if you have tests that are getting blocked by firewalls / iptables. If you're interested in a test that checks iptables is running, I made a simple extension script I might be able to share.
The check is to ensure that the local (client) DNS service is not 'open'. That is, that it will not resolve queries from external sources. (And hence prevents amplification attacks.) We run a separate client DNS test to ensure that local resolution is working, and, of course, a 'proc' check that 'named' is running.
The 'dns' test/ICMP problem has only just appeared when we moved the monitoring server. But without knowing what it was that the test was trying to resolve made it a bit difficult to diagnose.
John.
-- John Horne | Senior Operations Analyst | Technology and Information Services University of Plymouth | Drake Circus | Plymouth | Devon | PL4 8AA | UK
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