a question about tunnels

["marcelo bagnulo" <mbagnulo@ing.uc3m.es>]

Hi,

I have a very simple question about tunnels, but i am a bit confused by what
i have found in the specs, so perhaps someone could help me.

The question is: what is the behaviour of a host, that doesn't have any
configured tunnel, when it receives a tunneled packet addressed to him (both
destination addresses, inner and outer, are assigned to the host)?

Suppose that you have a host A with a single IP address IPA
The host receives a IP in IP encapsulated packet
The inner IP header contains destiantion address IPA and source address IPB
The outer IP header contains destiantion address IPA and source address IPC
The Host A has no configured tunnel With IPC

What does the host does with this packet?

I would expect that the packet is discarded. This IMHO would be the
behaviour coherent with the proposed processing of the HoA option of MIPv6.

However, in RFC 2003 (security considerations), it is stated that:

Host implementations that are capable of receiving encapsulated IP
datagrams SHOULD admit only those datagrams fitting into one or more
of the following categories:

[...]
    -  The encapsulated (inner) datagram is addressed to a network
       interface belonging to the decapsulator

So, RFC 2003 recomends that nodes should accept these packets...

Is this correct?
I mean, if this is so, the transport layer survivability problem could be
easier, i guess

Thanks, marcelo