Subject: Re: [Softwires] I-D Action: draft-ietf-softwire-map-12.txt

From: "Leaf Yeh" <[email-masked]>
Date: Sun, 15 Feb 2015 16:20:50 +0800

I got a late read on this draft, and may find some editorial nits:

#1. In sec. 3,

   "  End-user IPv6 prefix:   The IPv6 prefix assigned to an End-user CE by

                           other means than MAP itself.  E.g.,

                           Provisioned using DHCPv6 PD [RFC3633],

                           assigned via SLAAC [RFC4862], or configured

                           manually.  It is unique for each CE. "

Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the
subnet ID) in Fig.3?

But in sec. 5.2,

"  The MAP IPv6 address is created by concatenating the End-user IPv6

   prefix with the MAP subnet identifier (if the End-user IPv6 prefix is

   shorter than 64 bits) and the interface identifier as specified in

   Section 6.  "

Q. Does the above means ' End-user IPv6 prefix ' does not include 's bits'
(the subnet ID) in Fig.3? I guess we could include 's bits' (the subnet ID=
MAP subnet identifier) into ' End-user IPv6 prefix '.

And in sec. 6,

"  If the End-user IPv6 prefix length is larger than 64, the most

   significant parts of the interface identifier is overwritten by the

   prefix.  "

Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the
subnet ID) in Fig.3?

#2. In sec. 5.1,

"     For 'a' > 0, A MUST be

      larger than 0.  This ensures that the algorithm excludes the

      system ports.  For the default value of a (6), the system ports,

      are excluded by requiring that A be greater than 0.  Smaller

      values of a excludes a larger initial range.  E.g., a = 4, will

      exclude ports 0 - 4095.  The interval between initiaL port numbers

      of successive contiguous ranges assigned to the same user is

      2^(16-a).   "

I prefer the above sentence could be 

"     For 'a' > 0, 'A' MUST be 

      larger than 0.  This ensures that the algorithm excludes the

      system ports.  Smaller

      values of 'a' excludes a larger initial range; e.g. 'a' = 4, will

      exclude ports 0 - 4095.  The interval between initial port numbers

      of successive contiguous ranges assigned to the same user is

      2^(16-a).   "

#3. In Fig.7 of sec. 5.3,

“                   +----------+         +------------+

                   |IPv4  sufx|         |Port-Set ID |

                   +----------+         +------------+  ”

I prefer the above ‘sufx’ could to be ‘suffix’.

#4. In sec.6,

“  The PSID field is left-padded to create a

   16 bit field.  For an IPv4 prefix or a complete IPv4 address, the

   PSID field is zero.”

Q. Does the about ‘zero’ means the value of the PSID=0x 00, or the length
of the PSID is zero? I guess it means the former, right?

#5. In Fig.8 of sec.6,

“The Interface identifier format of a MAP node is described below.

  |          128-n-o-s bits          |

   | 16 bits|    32 bits     | 16 bits|

   +--------+----------------+--------+

   |   0    |  IPv4 address  |  PSID  |

   +--------+----+-----------+--------+  ”

I think BR does not need to use the above IID. I prefer to replace the word
‘MAP node’ to be ‘MAP CE’. Right?

The above format looks like ‘128-n-o-s =64, but that is not always true. I
prefer the IID format of MAP CE could be:

  |          128-n-o-s bits          |

   | <=16 bits|    32 bits     | 16 bits|

   +--------+----------------+--------+

   |   all 0s    |  IPv4 address  |  PSID  |

   +--------+----+-----------+--------+  ”

#6. In sec. 8.1,

“  Secondly, the node extracts the source IPv4

   address and port from the IPv4 packet embedded inside the IPv6

   packet.  If they are found to be outside the acceptable range, the

   packet MUST be silently discard and a counter incremented to indicate

   that a potential spoofing attack may be underway.”

I guess the better to substitute the above word ‘embedded’ could be
‘encapsulated’, right?

#7. In sec. 11

“     They cannot

      exist with MAP because each BRs checks that the IPv6 source

      address of a received IPv6 packet is a CE address based on

      Forwarding Mapping Rule. ”

I think BRs check that the IPv6 source address of a received IPv6 packet is
a CE address based on Basic Mapping Rule, and check that the IPv6
destination address of a received IPv6 packet is a CE address based on
Forwarding Mapping Rule, right?

Best Regards,

Leaf

-----Original Message-----
From: Softwires [mailto:[email-masked]] On Behalf Of
[email-masked]
Sent: Monday, November 24, 2014 3:39 PM
To: [email-masked]
Cc: [email-masked]
Subject: [Softwires] I-D Action: draft-ietf-softwire-map-12.txt

A New Internet-Draft is available from the on-line Internet-Drafts
directories.

This draft is a work item of the Softwires Working Group of the IETF.

        Title           : Mapping of Address and Port with Encapsulation
(MAP)

        Authors         : Ole Troan

                          Wojciech Dec

                          Xing Li

                          Congxiao Bao

                          Satoru Matsushima

                          Tetsuya Murakami

                          Tom Taylor

         Filename        : draft-ietf-softwire-map-12.txt

         Pages           : 32

         Date            : 2014-11-23

Abstract:

   This document describes a mechanism for transporting IPv4 packets

   across an IPv6 network using IP encapsulation, and a generic

   mechanism for mapping between IPv6 addresses and IPv4 addresses and

   transport layer ports.

The IETF datatracker status page for this draft is:

 <https://datatracker.ietf.org/doc/draft-ietf-softwire-map/>
https://datatracker.ietf.org/doc/draft-ietf-softwire-map/

There's also a htmlized version available at:

 <http://tools.ietf.org/html/draft-ietf-softwire-map-12>
http://tools.ietf.org/html/draft-ietf-softwire-map-12

A diff from the previous version is available at:

 <http://www.ietf.org/rfcdiff?url2=draft-ietf-softwire-map-12>
http://www.ietf.org/rfcdiff?url2=draft-ietf-softwire-map-12

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:

 <ftp://ftp.ietf.org/internet-drafts/> ftp://ftp.ietf.org/internet-drafts/

_______________________________________________

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 <mailto:[email-masked]> [email-masked]

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---

From: Ole Troan <[email-masked]>
Date: Mon, 16 Feb 2015 11:59:01 +0100

Leaf,

thanks, let's see if we can get these in during the AUTH48.

cheers,
Ole

> On 15 Feb 2015, at 9:20 , Leaf Yeh <[email-masked]> wrote:
> 
> Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the subnet ID) in Fig.3?
> 
> But in sec. 5.2,
> Q. Does the above means ' End-user IPv6 prefix ' does not include 's bits' (the subnet ID) in Fig.3? I guess we could include 's bits' (the subnet ID= MAP subnet identifier) into ' End-user IPv6 prefix '.
> 
> And in sec. 6,
> Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the subnet ID) in Fig.3?
> 
> 
> #2. In sec. 5.1,
> "     For 'a' > 0, A MUST be
> Q. Does the about ‘zero’ means the value of the PSID=0x 00, or the length of the PSID is zero? I guess it means the former, right?
> 
> 
> #5. In Fig.8 of sec.6,
> I think BR does not need to use the above IID. I prefer to replace the word ‘MAP node’ to be ‘MAP CE’. Right?
> The above format looks like ‘128-n-o-s =64, but that is not always true. I prefer the IID format of MAP CE could be:
>   |          128-n-o-s bits          |
> I guess the better to substitute the above word ‘embedded’ could be ‘encapsulated’, right?
> 
> 
> #7. In sec. 11
> “     They cannot
> I think BRs check that the IPv6 source address of a received IPv6 packet is a CE address based on Basic Mapping Rule, and check that the IPv6 destination address of a received IPv6 packet is a CE address based on Forwarding Mapping Rule, right?
> 
> 
> Best Regards,
> Leaf
> 
> 
> 
> From: Softwires [mailto:[email-masked]] On Behalf Of [email-masked]
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>         Title           : Mapping of Address and Port with Encapsulation (MAP)
>         Authors         : Ole Troan
>                           Wojciech Dec
>                           Xing Li
>                           Congxiao Bao
>                           Satoru Matsushima
>                           Tetsuya Murakami
>                           Tom Taylor
> Please note that it may take a couple of minutes from the time of submission until the htmlized version and diff are available at tools.ietf.org.
> 
> ftp://ftp.ietf.org/internet-drafts/
> 
> [email-masked]

---

From: Ted Lemon <[email-masked]>
Date: Mon, 16 Feb 2015 09:11:41 -0500

> thanks, let's see if we can get these in during the AUTH48.

There's still time to get them in as an RFC editor note if you want (sorry about that--I'm waiting on one last thing, which I should have tomorrow).

---

From: Ole Troan <[email-masked]>
Date: Fri, 20 Feb 2015 11:41:29 +0100

Leaf,

> Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the subnet ID) in Fig.3?

no, it is e.g. the /56 delegated to the end-user.

> Q. Does the above means ' End-user IPv6 prefix ' does not include 's bits' (the subnet ID) in Fig.3? I guess we could include 's bits' (the subnet ID= MAP subnet identifier) into ' End-user IPv6 pr…

correct, the subnet-id is not included in the End-user IPv6 prefix.
the End-User IPv6 prefix is the "name" for the address block that the ISP gives to the subscriber.

> Q. Does the above means ' End-user IPv6 prefix ' includes 's bits' (the subnet ID) in Fig.3?

still not.

>       of successive contiguous ranges assigned to the same user is

I agree that we should tag 'a'. I'll add that.

> #3. In Fig.7 of sec. 5.3,

ack.

> Q. Does the about ‘zero’ means the value of the PSID=0x 00, or the length of the PSID is zero? I guess it means the former, right?

correct.

>    | 16 bits|    32 bits     | 16 bits|

correct, but that leads us back to the discussion if the BR should be part of the MAP domain or not. that is should it be possible to reach an address of the BR using IPv4. that's why it says MAP node instead of MAP CE.

>    | <=16 bits|    32 bits     | 16 bits|

whenever we speak about an IPv6 Internet ID it is 64 bits long. I'd rather not that we change that here.
I do see what you are saying though.

> I guess the better to substitute the above word ‘embedded’ could be ‘encapsulated’, right?

yes, thanks.

> I think BRs check that the IPv6 source address of a received IPv6 packet is a CE address based on Basic Mapping Rule, and check that the IPv6 destination address of a received IPv6 packet is a CE a…

no, the destination IPv6 address is the BR address, and there is no point checking that.

cheers,
Ole