Don't forget the ARP protocol -- if a destination is not in the local system's ARP cache, the lower layer code in the IP stack discards the first packet and generates an ARP broadcast. The assumption (I guess) is that the discarded packet will be retransmitted. You might look for the "knobs" on fping to control timeouts and retry counts.
GLH
From: Josh Luthman [mailto:user-4c45a83f15cb@xymon.invalid] Sent: Wednesday, November 21, 2007 1:13 AM
To: user-ae9b8668bcde@xymon.invalid
Subject: Re: RE: Re: [hobbit] Hobbit CONN questions
Concerning fping options, I have some RRD graphs that show enormous pings to some of our customer's (upwards of 800ms) because as the radio doesn't pass any traffic it sits there and when someone first looks for it, it acts kind of dumb.
What delegates how often the FPING command is issued? I'm not looking for the arguments for fping itself, but rather how hobbitd kicks fping into gear.
I would like to increase the rate of the pings and see if that helps. I'm running a continuous ping over night to see if that changes the graph or if it really does spike to that outrageous height.
Josh
On 11/9/07, user-08b3b26d089f@xymon.invalid <user-08b3b26d089f@xymon.invalid > wrote:
-----Message d'origine-----
De : Henrik Stoerner [mailto: user-ce4a2c883f75@xymon.invalid]
Envoyé : vendredi 9 novembre 2007 08:23
À : user-ae9b8668bcde@xymon.invalid
Objet : Re: RE: Re: [hobbit] Hobbit CONN questions >
On Fri, Nov 09, 2007 at 08:14:32AM +0100,
user-08b3b26d089f@xymon.invalid wrote:
I'm just wondering what triggers in the Hobbit code is used
to make a RED ping status :
- after just one no echo-reply each 5min ?
- after a couple of no echo-reply ? How much ?
- What is the timeout used to declare the host unreachable ? >
It goes red when the ping utility that is used (fping or hobbitping)
says that the host did not respond. How many pings are sent
and what the
timeouts are is decided by the ping tool; see their man-pages for > details. You can tune this through commandline options for the ping
tool, these go into the FPINGCMD setting in hobbitserver.cfg
Henrik
Got it, options must be put in the hobbitserver.cfg . Thanks for the info!
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