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From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
To: "Hannes Mehnert" <hannes@mehnert.org>
Cc: "FreeBSD Net" <freebsd-net@freebsd.org>
Subject: Re: dupliceated icmp echo request
Date: Tue, 13 Sep 2016 16:21:36 +0000
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On 13 Sep 2016, at 15:39, Hannes Mehnert wrote:

> hello,
>
> (sorry in case this is the wrong mailing list)

freebsd-net might be better; which I put on CC:.


> while doing some network testing, I discovered that my FreeBSD 
> (r304285,
> but likely earlier + released ones as well) sends out two
> (bytewise-)identical ICMP echo requests shortly after each other when 
> I
> ping the broadcast (IPv4) address on an interface [tested with: 
> tap,em,iwm].
>
> This behaviour does not meet my expectations - is there any specific
> reason for this behaviour; it behaves well (sending out a single ICMP
> echo request) if I ping a unicast host.

Asking for a command line seems strange;  but given I am replying, is 
there any delay between the two packets?  If you ktrace ping, do you see 
multiple send calls for the same data?

/bz