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Re: [Fwd: I-D ACTION:draft-vandevelde-v6ops-nap-01.txt]

Hi Pekka,

Thanks for input. Before further digestion of the feedback have a look
at the thoughts below.

At 11:53 7/02/2005 +0200, Pekka Savola wrote: 
  o  The technology to enable source-routing on a network
      infrastructure has been enhanced to allow this feature to
      function, without impacting the processing power of intermediate
      network devices.  The only devices impacted with the
      source-routing will be the source and destination node and the
      intermediate source-routed nodes.  This impact behavior is
      different if IPv4 is used, because then all intermediate devices
      would have had to look into the source-route header.

==> again, this is not correct AFAIK.  IPv4 source routing can be used in a
similar "loose" mode as IPv6, so there is no technical differenceto IPv6
source routing.


I expected this comment to pop-up ;-), thus i did further research on this with the help of Eric.

<snip>
IETF STD5 about the IP protocol itself specifically states that the source route option is used by gateways (and not only by end node):

on page 18:

 The loose source and record route (LSRR) option provides a means
 for the source of an internet datagram to supply routing
 information to be used by the gateways in forwarding the
 datagram to the destination, and to record the route
 information.

and later on page 21:

 When an internet module routes a datagram it checks to see if
 the record route option is present.  If it is, it inserts its
 own internet address as known in the environment into which this
 datagram is being forwarded into the recorded route begining at
 the octet indicated by the pointer, and increments the pointer
 by four.

<end snip>

My understanding of this is that all routers MUST have a look at the IPv4 options
if LSRR is available, and this is different with IPv6.

Cheers,
G/