[51435] in North American Network Operators' Group
Re: IPv6 Interview Questions and critic
daemon@ATHENA.MIT.EDU (Peter John Hill)
Tue Aug 27 14:44:11 2002
Date: Tue, 27 Aug 2002 14:43:38 -0400
Cc: <nanog@merit.edu>
To: Joe Baptista <baptista@dot-god.com>
From: Peter John Hill <peterjhill@cmu.edu>
In-Reply-To: <Pine.LNX.4.33.0208271036220.8174-100000@dot-god.com>
Errors-To: owner-nanog-outgoing@merit.edu
On Tuesday, August 27, 2002, at 10:41 AM, Joe Baptista wrote:
> Ipv6 uses 128 bits to provide addressing, routing and identification
> information on a computer. The 128-bits are divided into the left-64
> and
> the right-64. Ipv6 uses the right 64 bits to store an IEEE defined
> global
> identifier (EUI64). This identifier is composed of company id value
> assigned to a manufacturer by the IEEE Registration Authority. The
> 64-bit
> identifier is a concatenation of the 24-bit company_id value and a
> 40-bit
> extension identifier assigned by the organization with that company_id
> assignment. The 48-bit MAC address of your network interface card is
> also
> used to make up the EUI64.
Since it so easy for a host (relative to ipv4) to have multiple ip
addresses, I like what Microsoft has done. If told by a router, a Win
XP box will assign itself a global unicast address using EUI-64. It
will also create a global unicast anonymous address. This will not be
tied to the hardware, and the OS will also limit how long it uses that
address before deprecating that address and creating a new preferred
anonymous address. I can see servers using the EUI-64 address, while
clients use the anonymous address. It will allow servers to narrow down
who is accessing their servers to a 64 bit subnet. That will be good
enough for most statistics, but will make it more difficult to do the
scarier tracking of users.
I have noticed that the Linux and Mac OS X ipv6 implementations so not
create the private addresses automatically.
Peter Hill
Network Engineer
Carnegie Mellon University
