Subject: RE: class E address

From: Mohammed Sqalli <[email-masked]>
Date: Mon, 10 Jun 2002 15:38:17 -0400

Check this RFC for the information you need:
http://www.ietf.org/rfc/rfc1166.txt

Regards,
Mohammed.

-----Original Message-----
From: Nguyen Thi Mai Trang [mailto:[email-masked]]
Sent: Monday, June 10, 2002 2:33 PM
To: [email-masked]
Subject: class E address

Hi everybody,

I have a question about class E IP address. I read a book which indicate
that
class E IP address has the following format:
1111 xxxx . xxxx xxxx . xxxx xxxx . xxxx xxxx
Thus, the lowest address is 240.0.0.0 and the highest address is
255.255.255.254

Another document I read states that the format of class E IP address is:
1111 0xxx . xxxx xxxx . xxxx xxxx . xxxx xxxx

I try to verify in RFCs of IETF about this but I cannot. I read RFC 790,
791,
796 but they do not mention about it. Could you please give me the RFCs
indicating the format of class E?

In the first case I describe in this message, I wonder why the lowest
address
of class E is not 240.0.0.1 because the adress with all 1 and all 0 have
special meanings (all 0 means "this" and all "1" means broadcast).

Thank you very much,
Mai Trang

---

From: Bob Braden <[email-masked]>
Date: Mon, 10 Jun 2002 20:18:24 GMT

*> 
  *> In the first case I describe in this message, I wonder why the lowest address
  *> of class E is not 240.0.0.1 because the adress with all 1 and all 0 have
  *> special meanings (all 0 means "this" and all "1" means broadcast).
  *> 

Because the internal structure and semantics of a class E address are
totally undefined.  Maybe the low order bits are NOT a host address,
for example.  Note that class D addresses were reserved for many years,
until IP multicast was invented around 1988 and assigned to class D.
Then class E became reserved.  If/when we find a use of class E
addresses, presumably class F will become reserved.

Bob Braden

  *> Thank you very much,
  *> Mai Trang
  *>