Subject: Re: ICMP messages.
To: Rune Pedersen <>
From: None <>
List: tech-net
Date: 09/22/2000 00:25:21
>As far as I can see, none of the 3 programs mentioned do receive ICMP
>messages of type 1,2 or 4. In fact, my program is based upon some of the
>ping6 code. Stevens "Network programming. Networking APIs: Sockets and
>XTI vol 1" does mention that type 1,2 and 4 ICMPv6 messages generate an
>errno in userspace, but are received and processed by the kernel only.
>The rest of
>the messages (like echo reply, type 128) are handled by user process
>according to the same book.

	if my memory serves, the above book describes incorrectly about how
	ICMPv6 socket behaves (in terms of IPv6 header on the socket data -
	RFC2292 specifiese that there will be  no IPv6 header on the socket
	data, while the book wrongly describes that IPv6 header will be present
	like IP_HDRINCL case).  I suggest you to take a look at RFC2292, not
	the Stevens book for this (I agree in most cases, the book has the
	definitive answer.  but in this case, it does not).

	IPv6 ICMP code throws up packets with any ICMPv6 type/code to the
	userland, even for type 1/2/4.  i believe you have some issue in
	userland program.