IPv4-mapped IPv6 addresses

Julio Baixauli baixauli@mat.upc.es
Mon, 18 Dec 2000 14:13:42 +0100


	Hello!

	I need an explanation about IPv4-mapped addresses... 

	I'm programming a client application for test purposes. Basically, I
open a socket and connect that socket to an IPv6 address. Next, I read
characters from that socket.

	There is no problems when I try to connect to global-scope addresses,
like 3ffe:XXXXXXXXXX. In this cases I can connect.
	The problem comes when I try to connect to IPv4-mapped addresses. In
this cases connect returns 'no route to host' or 'network is
unreachable'. This is false!! because I add a route to IPv4-mapped
addresses, and when I ping these addresses I can see, at least, ICMP
Neighbor Solicitation, for the gateway, on the net.

	So... what's failing?
	Do kernel any diferences between raw-sockets (ping) and stream-sockets
(tcp)?
	Are there any implications with IPv4-mapped addresses?
	I've no idea about what happens...

	Thank you very much, and I'm sorry for my horrible english.

-- 
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	Julio Baixauli Garreta
	baixauli@mat.upc.es

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