Subject: RE: TECH-OMISSION (-protocol): Partial IPs with CIDRs allowed?

From: "Nate Leon" <[email-masked]>
Date: Wed, 8 Sep 2004 09:39:36 -0700

Hmmm... so "64/8" would be valid ?

I'm not very comfortable with that.

n8

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]] On Behalf Of Meng Weng Wong
Sent: Tuesday, September 07, 2004 7:02 PM
To: Max Kanat-Alexander
Cc: [email-masked]
Subject: Re: TECH-OMISSION (-protocol): Partial IPs with CIDRs allowed?

On Tue, Sep 07, 2004 at 05:47:22PM -0700, Max Kanat-Alexander wrote:
| 
| 	Is it OK to write 1.2.3/24, or MUST I write 1.2.3.0/24? It would
be
| easier for implementation if the second form was required.
| 
| 	My apologies if this has already been mentioned or discussed
elsewhere.
| 

I have the feeling that people are going to write the first
form, so we might as well require implementations to support
it.  As long as it's not ambiguous, lazy is okay.

Similarly "ipv4" and "ipv6" being synonyms for "ip4" and
"ip6", and "a:1.2.3.4" being interpreted as "ip4:1.2.3.4".
That seems to happen rather often.

---

From: "william(at)elan.net" <[email-masked]>
Date: Wed, 8 Sep 2004 10:35:16 -0700 (PDT)

> I'm not very comfortable with that.

I'm not happy about it either and always used full cidr notaation
(64.0.0.0/8) but 64/8 is unfortunetly a valid representation of cidr.
I've had discussions about it before year ago in regards to ip whois and 
in the end a text was found from some old RFC which specified it.
I'll try to find those old emails and then post to the list.

I do note that since we do have classless cidr (RFC1519), old RFCs before 
that may not be correct. At the same time RFC1519 is not exactly great
guide either as its using cisco-specific syntax.

---
William Leibzon, Elan Networks:
 mailto: [email-masked]
Anti-Spam Research Worksite:
 http://www.elan.net/~william/asrg/

---

From: Mark Lentczner <[email-masked]>
Date: Wed, 8 Sep 2004 13:33:27 -0700

For the record, I don't think
	1.2.3/24
is or should be legal.

Thanks to the reference to RFC 3513, Section 2.2, this sort of thing is 
clearly not legal for ip6 networks (see the ABNF production for 
ip6-network in the protocol draft.)  If someone can supply me an 
equivalent reference for the ip4 notation, I'd be happy to include it.

I also don't think "ipv4:" should be a synonym for "ip4:".  Note, that 
since the standard is built on RFC 2234 for syntax definitions, all 
keywords are case independent:  "IP4:" is a synonym for "ip4:".

In general, I subscribe to the philosophy that the spec should be clear 
as to what is legal, and implementations should be ruthless in 
rejecting things that are malformed, misspelt, or otherwise broken.  
Just because the underlying representation is text doesn't mean that it 
isn't a protocol.

I also don't believe that the spec has to constantly say "We really 
mean it here, in this case you MUST MUST MUST follow the syntax."  That 
sort of thing should be implicit for the whole spec and if you start 
putting them in, then people feel free to play loosey-goosey with the 
rest.

That said, Wayne, if there are areas of protocol that are actually too 
liberal in what they accept, I would be happy to tighten them up.

	- Mark