[Nagiosplug-devel] Check_ping question

[Robert Nelson]

> Nonsensical. The timeout for iterative plugins should always be 
> calculated based on the sum of per-iteration timeouts (in 
> this case, 5 
> seconds * 3 packets).

Yes, but what I'm really looking for is a real "check-host-alive". I
don't want a status report, I just want a PASS/FAIL result. Since Nagios
seems configured to use check_ping for it, I am not looking for it to be
an iterative plugin in this case.

> > I end up with an *effective* timeout
> > value of (5000.0 / 1000.0 * 3 + 3 =) 18 seconds. This seems 
> "broken" to
> > me.
> > 
> 
> It isn't. If you specify a per-packet timeout value of 5 seconds and 
> send 3 packets that means the complete timeout must be at 
> least equal to 
> 15 seconds (I don't know where those extra three come from), 
> otherwise 
> the per-packet timeout wouldn't make sense (should you count 
> packets as 
> lost if they're not even sent?).

I guess I also am confused on this one, as /bin/ping on most OS's will
send packet 2 at 1000ms, and packet 3 at 2000ms, with a 5000 ms timeout,
that's 7.0000000001 seconds total. Why are we going all the way up to
18, or even 15 seconds then?


> > I ended up commenting out the last three lines quoted from 
> check_ping.c
> > and recompiling it. I'm just curious whether this is 
> behavior by design
> > or by error, and whether I need to make notes about it for when
> > plugins-1.3.2 comes out. Thanks!
> > 
> 
> It's obviously by design, and 1.3.2 won't come out. They're at 1.4.0 
> now. What would be good would be to remove the timeout value, 
> but that 
> would make a LOT of configurations out there return UNKNOWN instead.

I'll note that. I don't mind the way it calculates how long it *should*
take. To me it appears that a specified "timeout" value should not be
overridden, though.

Rob Nelson
Network Engineer
Windchannel Communications
919-538-6326