Re: [DNA] Prefix information for link identification in DNA

[Erik Nordmark <erik.nordmark@sun.com>]

Bernard Aboba wrote:
>>How can it be made sure that if the node moves from one adhoc network to
>>another the "network anchor" identities won't happen to be the same?
> 
> 
> In DNAv4, the "network anchor" identities are defined to include both the IP
> address and the MAC address, so that duplication of both would be required
> to cause confusion. 
> 
> This works as long as the "network anchor" is actually an anchor, not a buoy
> -- it cannot also be mobile.  

Can't it be confused in other cases?

Suppose I have a server with VLAN support that is part of multiple 
VLANs. The server uses the same MAC address on all its VLANs as is 
normal with VLAN capable network interfaces.

Suppose in addition the multiple VLANs are separate private address 
space domains - all using 10.0.0.0/8 addresses.

Now the server can have the same IP address on all its VLANs as well
(presumably requires running Xen or vmvare on the server to make sure 
the server doesn't get confused).

Thus on VLAN 1 the server has MAC address M1 and IP address 10.1.2.3.
The default routers on VLAN1 are 10.0.0.1 and 10.0.0.2.

On VLAN 2 the server has MAC address M1 and IP address 10.1.2.3.
The default routers on VLAN2 (different than on 1) are 10.0.1.1 and 
10.0.1.2.

In this case the fact that MAC address M1 can be reached at IP address 
10.1.2.3 does not mean that the IP configuration is the same; the host 
needs to get the different default routers when moving between the links.

    Erik