flappingstart alert

[jtintegration]

I have question regarding flappingstart/flappingstop alert. I am not sure why a switch would be flapping. I check the log of the switch and there is no indication of going offline, therefore how does Nagios determine if host is flapping?


thanks

[kyang]

Hi @jtintegration,

Flapping occurs when a service or host changes state too frequently, resulting in a storm of problem and recovery notifications.
Flapping can be indicative of configuration problems (i.e. thresholds set too low), troublesome services, or real network problems.

Related to a switch, could be low thresholds on ports?

Here's a doc on detection and handling of the Flapping state.
https://assets.nagios.com/downloads/nag ... pping.html


Along with another forum that explains how flapping works as an example.

https://support.nagios.com/forum/viewto ... 39&p=56595

Let me know if you have more questions. Or a Nagios admin can chime in.

[dwhitfield]

Thanks @kyang!

I check the log of the switch and there is no indication of going offline

Is there any network device XI and the switch? Are you monitoring the XI server itself? Is network connectivity a problem on the XI server?

If you want to take a look at the XI operation for issues, can you PM me your Profile? You can download it by going to Admin > System Config > System Profile and click the ***Download Profile*** button towards the top. If for whatever reason you *cannot* download the profile, please put the output of View System Info (5.3.4+, Show Profile if older) in the thread (that will at least get us some info). This will give us access to many of the logs we would otherwise ask for individually. If security is a concern, you can unzip the profile take out what you like, and then zip it up again. We may end up needing something you remove, but we can ask for that specifically.

After you PM the profile, please update this thread. Updating this thread is the only way for it to show back up on our dashboard.

[jtintegration]

Here is the PM that you requested, keep in mind that I have 240 plus hosts and 480 plus services that I am monitoring, therefore don't think it is nagios server itself. I only get flapping for about 5 or so hosts.

[dwhitfield]

I only get flapping for about 5 or so hosts.

Any chance those are behind the same network device? Perhaps on the same vlan?

There's no flapping in your nagios.log. Do you know when the flapping started? What are the names of the hosts that are flapping? Is it just the hosts that are flapping, or is it services?

[jtintegration]

They are hosts flapping. It happen yesterday.

[dwhitfield]

Any chance those are behind the same network device? Perhaps on the same vlan?

Can you answer the above questions? Also, subnet info could be useful.

If you want us to take a look we'll need yesterday's nagios.log, which should be in /usr/local/nagios/var/archives (and have the date associated with the file name).

[jtintegration]

The nagios server is one one vlan and hosts(hp procurves) are on different vlan and subnet. Please keep in mind that I am not having problem with all host, just one or two are flapping. I also included the log file from yesterday that host (10.4.0.10) is flapping.

[dwhitfield]

The log is from a month ago.

I apologize for not being clear about my question. What I'm asking is about the few that are flapping. You said there were 5. Now you say there are one or two. I'm trying to figure out if there is some commonality between these hosts...some reason they would all be flapping at the same time.

Also, are they still flapping? If they are not still flapping, I think you can probably just chalk it up to a network glitch and not worry about it.