Subject: example IP addresses and domain names in Internet-Drafts

From: Rohan Mahy <[email-masked]>
Date: Tue, 9 Aug 2005 07:53:09 -0700

Hi,

We've all been instructed to use private IPv4 addresses in our 
examples.  I think this has an unfortunate negative consequence, which 
is that I've seen implementors come to the conclusion that they really 
should use private addressing for some particular extension or 
protocol.  This problem is much worse when we are defining protocols 
like STUN which deal with NAT mappings.  It would be much clearer to 
give an example with a public IP address and a private IP address.

Likewise describing communication between two domains (example.com and 
example.org) is not very clear because the two domains are so visually 
similar in the examples.  When I am doing training I get to use names 
like acme.com and bigU.edu which are short and distinctive.  Tacking on 
something distinctive to example.com and example.edu is ok, but long 
domain names are problematic in examples limited to 72-characters of 
text.  I have some URIs which are already too long to display on a 
single line.

What have folks done about this in the past?  Could we get another 
permanent IPv4 and a new IPv6 address range for example usage?  How 
about a new domain name?

I think the IPv6 example address would be especially useful for Apps 
layer folks.

thanks,
-rohan

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From: "Steven M. Bellovin" <[email-masked]>
Date: Tue, 09 Aug 2005 11:53:15 -0400

In message <[email-masked]>, Rohan Mahy writes:
>examples. 

No, you're supposed to use the "reserved for documentation" addresses, 
which are not 1918 addresses.  In particular, RFCs should use
192.0.2.0/24, which is listed in RFC 3330 as used for that purpose.  
(During my time on the IESG, the only times we (knowingly) permitted 
use of 1918 addresses was when the document really needed more than one 
block.)

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb

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From: Rohan Mahy <[email-masked]>
Date: Tue, 9 Aug 2005 08:58:49 -0700

Hi,

Is there an IPv6 equivalent for this yet?

thanks,
-rohan

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From: Bill Fenner <[email-masked]>
Date: Tue, 9 Aug 2005 12:09:33 -0400

>Is there an IPv6 equivalent for [192.0.2.0/24] yet?

Yes, it's 2001:db8::/32, described in RFC 3849.

  Bill

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From: Pete Resnick <[email-masked]>
Date: Tue, 9 Aug 2005 14:01:21 -0500

On 8/9/05 at 7:53 AM -0700, Rohan Mahy wrote:

>Likewise describing communication between two domains (example.com 
>and example.org) is not very clear because the two domains are so 
>visually similar in the examples.  When I am doing training I get to 
>use names like acme.com and bigU.edu which are short and 
>distinctive.  Tacking on something distinctive to example.com and 
>example.edu is ok, but long domain names are problematic in examples 
>limited to 72-characters of text.  I have some URIs which are 
>already too long to display on a single line.

Domain names with the top level ".example" domain are also OK.

pr
-- 
Pete Resnick <http://www.qualcomm.com/~presnick/>
QUALCOMM Incorporated - Direct phone: (858)651-4478, Fax: (858)651-1102

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From: Paul Hoffman <[email-masked]>
Date: Tue, 9 Aug 2005 14:27:53 -0400

It should not be all that difficult for the IETF to not get two /24s 
in different /8s for use in examples. Similarly, having a second 
domain name would be useful as well.

--Paul Hoffman, Director
--VPN Consortium

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From: Harald Tveit Alvestrand <[email-masked]>
Date: Mon, 15 Aug 2005 11:14:37 +0200

--On 9. august 2005 14:27 -0400 Paul Hoffman <[email-masked]> wrote:

> It should not be all that difficult for the IETF to not get two /24s in
> different /8s for use in examples. Similarly, having a second domain name
> would be useful as well.

"bear.example.org" and "rabbit.example.org" are somewhat more distinct than 
example.com and example.org....

                 Harald Alvestrand
       member, conspiracy to preserve the 3rd level of the DNS hierarchy

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From: Rohan Mahy <[email-masked]>
Date: Mon, 15 Aug 2005 08:06:54 -0700

Harald,

I like using the 3rd level of the hierarchy, but with 72 characters to 
work with, something like bear.example.com is often way too long.  For 
example, cat.ex.com and dog.ex.com  would be a significant improvement.

thanks,
-rohan

On Aug 15, 2005, at 2:14, Harald Tveit Alvestrand wrote:
>> in
> "bear.example.org" and "rabbit.example.org" are somewhat more distinct 
> than example.com and example.org....
>
>                 Harald Alvestrand

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From: Tony Hansen <[email-masked]>
Date: Mon, 15 Aug 2005 11:38:50 -0400

To reiterate and further Pete's observation, what's wrong with
cat.example and dog.example? It's only one character longer than cat.ex.com.

Besides, ex.com is already taken. :-)

	Tony Hansen
	[email-masked]

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From: Rohan Mahy <[email-masked]>
Date: Mon, 15 Aug 2005 09:34:16 -0700

FWIW, cat.example and dog.example are fine for me.  I was just 
responding to Harald's suggestion.

thanks,
-rohan