Subject: Re: disman issue REMOPS-7

From: [email-masked]
Date: Thu, 24 Jun 1999 09:59:29 -0400

Dave,

>disman issue REMOPS-7:

> >    pingCtlDataSize OBJECT-TYPE
> ...
> >           request is usually an ICMP message encoded
> >           into an IP packet.  An IP packet has a maximum size
> >           of 65535 octets.  Subtracting the size of the ICMP
> >           header (8 octets) and the size of the IP header
> >           (20 octets) yields a maximum size of 65507 octets."
>
> Might be helpful to say "Subtracting the size of the ICMP or
> UDP header (both 8 octets)..." since both are allowed.
...

>Randy: As a technical contributor, I agree with this clarification.

I can't see what is wrong with the existing text. An IP packet is
limit to 65535 octets. The text says that substracting the ICMP and IP
headers you end up with 65507. The IP header is 20 octets since no options
are specified. The ICMP header is 8 octets. 65535 - 28 is 65507.
What am I missing?

Ken

---

From: Dave Thaler <[email-masked]>
Date: Thu, 24 Jun 1999 13:16:56 -0400 (EDT)

> are specified. The ICMP header is 8 octets. 65535 - 28 is 65507.

You're missing the fact that pings can be sent via UDP, in which
case the size of the ICMP header is completely irrelevant.
The SIZE clause has to cover the UDP case, and this clarification
shows that the existing range works for UDP also.

-Dave