Subject: Regarding the pointer field in LSSR options of IP packet.

From: Shankar Agarwal <[email-masked]>
Date: Sun, 04 Jun 2000 19:52:52 +0530

Hi,
If there is any typing error in some RFC then what is the rule. Do we
correct it. I found one in the RFC792 where the 

IP Fields:

   Type

      15 for information request message;

      16 for information reply message.

   Code

      0

should have been

ICMP Fields:

   Type

      15 for information request message;

      16 for information reply message.

   Code

      0

Regards
Shankar

---

From: "C. M. Heard" <[email-masked]>
Date: Tue, 6 Jun 2000 00:17:54 -0700 (PDT)

Shankar Agarwal <[email-masked]> wrote:
>
> Can anyone tell me why the minimum value of the pointer in the LSSR option
> is 4. It says that it points to the next address with respect to the option
> field. Then shouldn't it be 3 (option type + length + pointer) rather then 4.
> Similarly for the pointer in the timestamp option it says that
> "The Pointer is the number of octets from the beginning of this
> option to the end of timestamps plus one (i.e., it points to the
> octet beginning the space for next timestamp).  The smallest
> legal value is 5.  The timestamp area is full when the pointer
> is greater than the length."

The pointers are 1-based, i.e., a pointer value of 1 would point to the
option type.

//cmh

---

From: Bob Braden <[email-masked]>
Date: Tue, 6 Jun 2000 15:44:11 GMT

*> Shankar Agarwal <[email-masked]> wrote:
  *> >
  *> > Can anyone tell me why the minimum value of the pointer in the LSSR option
  *> > is 4. It says that it points to the next address with respect to the option
  *> > field. Then shouldn't it be 3 (option type + length + pointer) rather then 4.
  *> > Similarly for the pointer in the timestamp option it says that
  *> > "The Pointer is the number of octets from the beginning of this
  *> > option to the end of timestamps plus one (i.e., it points to the
  *> > octet beginning the space for next timestamp).  The smallest
  *> > legal value is 5.  The timestamp area is full when the pointer
  *> > is greater than the length."
  *> 
  *> The pointers are 1-based, i.e., a pointer value of 1 would point to the
  *> option type.
  *> 
  *> //cmh
  *> 
  *> 

Yes.  

Some years ago I twigged Jon Postel about this precise issue.  As I
recall, he shrugged his shoulders and said something like "Well, I made
a choice, maybe not the choice I would make today, but... [that's the
way it is, learn to live with it!].

(The part in [] is my interpretation of his shrug).

Bob Braden

---

From: "Dawson, Peter D" <[email-masked]>
Date: Tue, 6 Jun 2000 16:44:14 -0000

->-----Original Message-----
->From: Bob Braden [mailto:[email-masked]]
->Sent: Tuesday, June 06, 2000 11:44 AM
->To: [email-masked]; [email-masked]
->Subject: Re: Regarding the pointer field in LSSR options of IP packet.
->
->Yes.  
->
->Some years ago I twigged Jon Postel about this precise issue.  As I
->recall, he shrugged his shoulders and said something like 
->"Well, I made
->a choice, maybe not the choice I would make today, but... [that's the
->way it is, learn to live with it!].
->
->(The part in [] is my interpretation of his shrug).
->
->Bob Braden

I think at that "time" [early '80'], someone had to make "some" 
decision's and Jon did, as he was the rfc editor... 

/pd