[smokeping-users] FPing alternative

[Israel Brewster]

On May 17, 2008, at 11:03 AM, Niko Tyni wrote:

> On Sat, May 17, 2008 at 02:20:04PM -0400, Mike Lerley wrote:
>
>> Fair enough; however, I have turned on and off all options I can  
>> find on the
>> router related to that sort of thing and nothing changes.  More  
>> importantly,
>> I can do this:
>>
>> root at george:~# ping -f tobeys.gotdns.com
>> PING tobeys.gotdns.com (24.39.29.68) 56(84) bytes of data.
>> .......................................
>> --- tobeys.gotdns.com ping statistics ---
>> 3609 packets transmitted, 3570 received, 1% packet loss, time 47185ms
>> rtt min/avg/max/mdev = 23.229/31.162/72.274/7.039 ms, pipe 6, ipg/ 
>> ewma
>> 13.078/27.893 ms
>>
>> Clearly, there is no packet rate limiting in effect here...
>
> It's most probably looking at the ICMP sequence number.  While the
> 'regular ping' increments the sequence number for each ping, fping
> apparently uses is as an index to the hosts it's pinging. So the first
> host gets sequence number 0 for all pings, the second one gets 1 etc.
>
> The device probably considers the unchanging sequence number an attack
> and stops responding.
>
> It should be quite easy to patch fping to store the information in the
> payload instead and increase the sequence number like the rest of the
> world does. No, no patch at least yet :)
>
> Cheers,

Now that is the best answer I have heard yet- it actually makes sense  
(to a degree, at least), and fits the observed facts. Any chance of  
such a patch being written by someone? I'd be happy to test it, if  
so... Actually, I'd almost be happy to write it, except I don't think  
my understanding of networks, ping payloads, and how this all works is  
quite up to the task :).

-----------------------------------------------
Israel Brewster
Computer Support Technician
Frontier Flying Service Inc.
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7250 x293
-----------------------------------------------
>
> -- 
> Niko
>
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