One of a pair of new hosts was causing the following Nagios alert today:<\/p>\n
Both of the new systems have the same configuration in theory, but based on the different results something clearly was overlooked.<\/p>\n I tried running NTP from the Nagios host:<\/p>\n Host 1<\/strong><\/p>\n Host 2<\/strong><\/p>\n The iptables rules look the same on both. The hosts are all on the same LAN, so there’s no firewall in the way.<\/p>\n Both systems are running Host 1<\/strong><\/p>\n Host 2<\/strong><\/p>\n Both systems are listening on port 123:<\/p>\n Host 1<\/strong><\/p>\n Host 2<\/strong><\/p>\n Finally, I found it. In the obvious place that perhaps I should have looked first. The And the first place I looked was iptables. Blame the firewall, after all. The configurations were both pushed to these systems via Ansible playbooks, but apparently I had not included the role that updates the chrony.conf file on the 2nd host. Looks like I need configuration management management!<\/p>\n","protected":false},"excerpt":{"rendered":" One of a pair of new hosts was causing the following Nagios alert today: CRITICAL: No response from NTP server Both of the new systems have the same configuration in theory, but based on the different results something clearly was overlooked. I tried running NTP from the Nagios host: Host 1 $ check_ntp -H ephemeralbox1.osric.net … Continue reading Nagios alert: CRITICAL: No response from NTP server<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[484,422],"tags":[443,348,442],"class_list":["post-2362","post","type-post","status-publish","format-standard","hentry","category-monitoring","category-sysadmin","tag-chrony","tag-nagios","tag-ntp"],"_links":{"self":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2362","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/comments?post=2362"}],"version-history":[{"count":6,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2362\/revisions"}],"predecessor-version":[{"id":2374,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2362\/revisions\/2374"}],"wp:attachment":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/media?parent=2362"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/categories?post=2362"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/tags?post=2362"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}CRITICAL: No response from NTP server<\/code><\/p>\n$ check_ntp -H ephemeralbox1.osric.net -w 0.1 -c 0.2
\nNTP OK: Offset -0.02545583248 secs|offset=-0.025456s;0.100000;0.200000;<\/code><\/p>\n$ check_ntp -H ephemeralbox2.osric.net -w 0.1 -c 0.2
\nCRITICAL: No response from NTP server<\/code><\/p>\nchronyd<\/code>:<\/p>\n[chris@ephemeralbox1 ssh]$ systemctl show chronyd | egrep '(ActiveState|SubState)'
\nActiveState=active
\nSubState=running<\/code><\/p>\n[chris@ephemeralbox2 ssh]$ systemctl show chronyd | egrep '(ActiveState|SubState)'
\nActiveState=active
\nSubState=running<\/code><\/p>\n[chris@ephemeralbox1 ssh]$ sudo lsof -i :123
\nCOMMAND PID USER FD TYPE DEVICE SIZE\/OFF NODE NAME
\nchronyd 3027 chrony 3u IPv4 1095448 0t0 UDP *:ntp<\/code><\/p>\n[chris@ephemeralbox2 ssh]$ sudo lsof -i :123
\nCOMMAND PID USER FD TYPE DEVICE SIZE\/OFF NODE NAME
\nchronyd 1241 chrony 3u IPv4 51276 0t0 UDP *:ntp<\/code><\/p>\n\/etc\/chrony.conf<\/code> file on Host 2 was missing the allow<\/code> line for the Nagios host:<\/p>\n# Allow NTP client access from Nagios host
\nallow 192.168.100.100<\/code><\/p>\n