Subject: [mif] #6: Lifetime field length should be 16bit for ND compatibility

From: "mif issue tracker" <[email-masked]>
Date: Wed, 01 Aug 2012 21:01:59 -0000

#6: Lifetime field length should be 16bit for ND compatibility

 Currently draft-ietf-mif-dhcpv6-route-option-04 specifies that the
 lifetime of a route (and implicitely of a default route) is to be 32bit
 length field.

 On another hand, the currently implemented default routes are
 implemented according to ND Neighbor Discovery, which uses route_r_
 lifetime on 16bit (RFC 4861 search "Router Lifetime").

 I think this is an issue.  It generates additional work to the
 implementer.  If one agrees that it is good to store the DHCP default
 route in the existing ND data structures, then one notices a conversion
 is needed.  If these lifetime fields were expressed in the same number
 of bits (preferably 16bit, because that exists already) then the
 implementer would be relieved from conversion work.

-- 
-------------------------+-------------------------------------------------
 Reporter:               |      Owner:  draft-ietf-mif-dhcpv6-route-
  alexandru.petrescu@…   |  option@…
     Type:  enhancement  |     Status:  new
 Priority:  minor        |  Milestone:  milestone1
Component:  dhcpv6       |    Version:
  -route-option          |   Keywords:
 Severity:  In WG Last   |
  Call                   |
-------------------------+-------------------------------------------------

Ticket URL: <http://trac.tools.ietf.org/wg/mif/trac/ticket/6>
mif <http://tools.ietf.org/mif/>

---

From: "mif issue tracker" <[email-masked]>
Date: Wed, 01 Aug 2012 21:02:43 -0000

Changes (by alexandru.petrescu@…):

 * cc: alexandru.petrescu@… (added)

  -route-option          |  Resolution:
 Keywords:               |

Ticket URL: <http://trac.tools.ietf.org/wg/mif/trac/ticket/6#comment:1>
mif <http://tools.ietf.org/mif/>

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 01 Aug 2012 16:57:52 -0700

MIF WG, Tomek,

What would text towards resolution of this issue look like?

In section 5.2:
> Route lifetime  32-bit unsigned integer.  Specifies lifetime of the
> route information, expressed in seconds (relative to the time the
> packet is sent).  There are 2 special values defined. 0 means that
> route is no longer valid and must be removed by clients.  A value of
>  all one bits (0xffffffff) represents infinity. means infinity.

Suggest new:

> Route lifetime  32-bit unsigned integer.
>
> Specifies lifetime of the route information, expressed in seconds
> (relative to the time the packet is sent). There are 2 special
> values defined. 0 means that route is no longer valid and must be
> removed by clients. A value of all one bits (0xffffffff) represents
> infinity.
>
> If compatibility with the Default Router List data structure of
> Neighbour Discovery is desired, and if this lifetime relates to a
> default route then the value 0 should not appear in this field; and
> the maximum value of this field should be 9000. The conversion
> between the 32-bit unsigned integer (required above) and the 16-bit
> unsigned integer (required by some ND implementations) can be
> realized in programming by cast operations. If the value of this
> Route lifetime field is larger than 9000 then the receiving Host (or
> Router) should use the value 9000 instead. If the value of this Route
> lifetime fielD is 0 then the receiving Host (or Router) should drop
> this packet.

What do you think?

Alex

Le 01/08/2012 14:01, mif issue tracker a écrit :
> lifetime of a route (and implicitely of a default route) is to be
> 32bit length field.
>
> implementer.  If one agrees that it is good to store the DHCP
> default route in the existing ND data structures, then one notices a
>  conversion is needed.  If these lifetime fields were expressed in
> the same number of bits (preferably 16bit, because that exists
> already) then the implementer would be relieved from conversion
> work.
>