Subject: [netlmm] draft-ietf-netlmm-pmip6-ipv4-support-01.txt

From: Behcet Sarikaya <[email-masked]>
Date: Wed, 22 Aug 2007 16:16:20 -0700 (PDT)

Hi Sri/ Ryuji,
  I saw the following sentences in the draft:
Unlike in DSMIP6, a mobile node in Proxy
   Mobile domain is NOT required to have an IPv6 home address for
   obtaining IPv4 home address mobility.MN also is NOT required to have an IPv6 home network prefix? BTW this sentence is repeated in other places as well.

As specified in the Proxy Mobile IPv6 specification [ID-PMIP6], this
   specification assumes that the link between the mobile access gateway
   and the local mobility anchor is a point-to-point link.MN-MAG link is a ptp link, why should MAG-LMA be a ptp link? Does this mean to say that MAG is a L2 bridge? I thought this had been rejected.

If a local mobility anchor
      is configured behind NAT, IPv4-LMAA is the IPv6 global address of
      the NAT box.How is it possible that an IPv4 address is an IPv6 address?

This draft nicely ties IPv4 home address with IPv4 home network prefix towards the implementation of per-MN prefixes in IPv4. What is missing is a little bit of guidance which is needed since IETF did not define IPv4 PD. My suggestion is to add it to the draft (the idea belongs to Dave Thaler): 
When LMA is behind NAT, LMA assigns IPv4 home network prefixes (or subnet masks) from 10.0 address space (RFC 1918) and IPv4 home address from the prefix. Using such an assignment scheme, close to 2^16 MN's can be supported.

Regards,

Behcet

_______________________________________________
netlmm mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/netlmm

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 23 Aug 2007 11:47:32 +0200

Behcet Sarikaya wrote:
[...]
> This draft nicely ties IPv4 home address with IPv4 home network 
> prefix towards the implementation of per-MN prefixes in IPv4. What is
>  missing is a little bit of guidance which is needed since IETF did 
> not define IPv4 PD.

(Errr... DHC WG is currently defining "IPv4 Subnet Allocation Option"
  draft-ietf-dhc-subnet-alloc-05.txt which is a reiteration of an older
  draft on this topic.)

> My suggestion is to add it to the draft (the idea belongs to Dave 
> Thaler): When LMA is behind NAT, LMA assigns IPv4 home network 
> prefixes (or subnet masks) from 10.0 address space (RFC 1918) and 
> IPv4 home address from the prefix. Using such an assignment scheme, 
> close to 2^16 MN's can be supported.

The recommendation sounds good to me.

However, haven't yet read the draft I don't know whether pmipv6-v4
supports LMA (HA) behind NAT.  DS-MIPv6 doesn't.  I don't mean it should.

Also, the recommendation on IPv4 or IPv6 address architecture and
deployment for pmipv6-v4 should be formulated as such, I mean just as an
example recommendation.  Because it is possible to be behind NAT and use
public address space, or any other thing imaginable... and people do it.

Alex

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please visit http://www.messagelabs.com/email 
______________________________________________________________________