Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!pasteur!ames!lll-winken!uunet!ingr!ed!sale
From: sale@ed.uucp (Ed Sale)
Newsgroups: comp.protocols.tcp-ip
Subject: ICMP Information Request Message format
Message-ID: <4483@ingr.com>
Date: 15 Mar 89 23:38:55 GMT
Sender: usenet@ingr.com
Reply-To: b11!ed!sale@ingr.com (Ed Sale)
Distribution: usa
Organization: Intergraph Corporation, Huntsville, AL
Lines: 28

RFC 792 when describing the Information Request message, states:

	This message may be sent with the source network in the IP header
	source and destination address fields zero (which means "this"
	network).  The replying IP module should send the reply with the
	address fully specified.  This message is a way for a host to 
	find out the number of the network it is on.

Douglas Comer in "Internetworking with TCP/IP", states:

	Machines use the ICMP information request message to obtain an
	Internet address for a network to which they attach; it is an
	alternative to RARP.

I'm confused.  Which does it do - get the network part of the internet
address (in which case how does it know what class network address it
is to determine how many bytes are host address?) - or get the entire
internet address translated from the hardware address in the physical
header - or both?


Ed Sale

...!uunet!ingr!b11!sale  or  b11!ed!sale@ingr.com

Ed Sale

..!uunet!ingr!b11!sale  or  b11!ed!sale@ingr.com