Re: LIN6 and multihoming (+sec)

[Masahiro Ishiyama <masahiro@wide.ad.jp>]

>>>>> On Wed, 22 Aug 2001 16:18:49 +0300 (EEST), Pekka Savola <pekkas@netcore.fi> said:

 > What I mean is that here, your "address" is derived from MAC address of
 > your network interface.  If you have two, you obviously have two
 > addresses.

	In LIN6, addresses (locators) that are assigned to ifs are
	derived from the unique LIN6 ID (64 bit node identifier)
	assigned to the node and a prefix, not from the MAC address of
	the network interface.

 > I also see a possible usage scenario (I'm not sure if this would be really
 > applicable/useful there though!), where a regular router provides two
 > network prefixes, and the LIN6 node would only have one NIC with two
 > prefixes (even "rapid renumbering" if you may).  In this kind of scheme,
 > LIN6 would be used to gain "provider independent prefix", non-breaking
 > connections when active prefix changes and static ipsec associations,
 > among others. However, now as there is only one NIC, there is only one
 > address.  How do you derive the second address?

	As you know, in IPv6, a node may be assigned multiple global
	addresses to an interface.


                            (Prefix Pa)
                             Path_A
                               -----\    |
                                     \   |
         Node_2 ---  R ...            R--+
            (Px:I2)                  /   |   Pa:I1
                               -----/    |-----Node_1(LIN6 ID=I1)
                               Path_B    |   Pb:I1
                              (Prefix Pb)

	Node_1 has one interface and two addresses(locators) are
	assigned: Pa:I1 and Pb:I1.
	Let us consider the case when Node_1 uses Pa:I1 as the current
	locator.  Assume that Path_A crashes, and Node_1 changes its
	current locator to Pb:I1 and updates its mapping.  When Node_2
	refreshes the mapping of Node_1, the destination address of
	packets to Node_1 will be changed to Pb:Ib.
	However, the established connections between Node_1 and Node_2
	remain undisturbed even after the path changes because the
	connections are established between LIN6_P(LIN6 Prefix)+I1 and
	LIN6_P+I2, independent of the locators: Pa:I1, Pb:I1.
	LIN6_P is a well-known constant.

masahiro