Introducing draft-denog-v6ops-addresspartnaming

Owen DeLong owen at
Sun Nov 21 19:52:49 CST 2010

> On Sun, Nov 21, 2010 at 5:15 PM, Owen DeLong <owen at> wrote:
>>> Imea nrea lly, what ifwe wrot eEng lish thew aywe writ eIPv 6add ress
>>> es? Looks pretty stupid without a floating separator, doesn't it?
>> If this were prose, sure. It isn't. It's an addressing scheme. I mean,
>> really, we don't question 99999-1520 or 408-555-1212 which
>> are much more like what we're talking about.
>> In fact, it would look pretty weird to most people if we started writing
>> 951-21-42-33 (or I bet they wouldn't expect that was a zip code in
>> any case). Similarly, if we start placing the separators in arbitrary
>> places in phone numbers, people get confused.
> That would be a more compelling argument if it accurately described
> phone number notation. It doesn't. "+44 121 410 5228," for example, is
> the phone number for parking services at Heathrow airport, exactly as
> described on's "contact us" page. No
> dashes at all, and not 10 digits.
Sure, but, try presenting a NANPA phone number in that format to just about
anyone in the US and you'll get a pretty perplexed look. In fact, many people
have a great deal of difficulty when confronted with +1 408 555 1212, let
alone something like +1 40 85 55 12 12 or any other derivitave you might
want to come up with.

> The Zip code's components also have meaning. The left 5 digits
> indicate the specific post office and the right 4 digits usually
> specify the internal box number used for sorting the mail.
Which is why I offered 951-21-42-33 as an alternative... Turns
out that has significance too... 951 is the bulk mail center. 21 is
the post office within the bulk mail center service area. 42
is the carrier route and 33 is of local significance within the
route. Most post offices have two zip codes... The second one
is usually the standard zip++ and is used for po boxes where
the format is BBBpX-XXXX whiere BBB is still the builk mail
center, but, X-XXXX is the P.O. Box.

We could also move on to SSNs which would confuse people
no end if you wrote them as 57523-1234 rather than as 575-23-1234.
In fact, you could have lots of fun writing zip codes as 951-21-4223
and SSNs as 57523-1234.
> IPv6 is one of very few addressing schemes in which the separators
> intentionally have no greater meaning within the protocol or its use.
> They're just there. If we want folks to understand that difference
> from their normal experience with addressing notations, we'll have to
> call attention to it by, for example, leaving the byte groupings
> formally unnamed.
I don't think leaving the hextets unnamed helps with that in any meaningful

As I said, the only thing you accomplish by leaving it formally unnamed
is to cause everyone to make up their own local name and expand the

>>>> Dash is a poor choice because it becomes potentially problematic
>>>> to know whether your cisco is telling you that:
>>>> 2001-0db8-5f03 is a MAC address or a /48 prefix.
>>> Cisco's expression of a MAC address is wrong anyway. Correct notation
>>> for a MAC address is separating each byte with a colon.
>> Doesn't matter... It's widespread and Cisco isn't the only one to use it.
> Just for my own edification, who else besides Cisco do you know who
> uses that notation for MAC addresses? I want some convincing before
> I'll accept the claim that it's widespread.
Cisco alone is a sufficient sample of the market to constitute widespread
usage. However, several router vendors that have cloned Cisco behaviors
and command-line syntax have also cloned this mess.

I don't recall their names for certain off the top of my head, but, I know I've
encountered it on non-Cisco routers.


> -Bill
> -- 
> William D. Herrin ................ herrin at  bill at
> 3005 Crane Dr. ...................... Web: <>
> Falls Church, VA 22042-3004

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