Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X"

Owen DeLong <> Fri, 01 November 2019 18:59 UTC

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From: Owen DeLong <>
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Date: Fri, 1 Nov 2019 11:58:35 -0700
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Subject: Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X"
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> On Nov 1, 2019, at 11:19 AM, wrote:
>>> So - TL;DR: We don't do "flash renumbering" for fun, on the other
>>> hand we also don't strictly follow RFC 4192.
>> Put another way, from the customer perspective…
>> “We don’t do flash renumbering for fun, but we do value our convenience
>> above the impact this has on our customers and therefore when we find it
>> convenient, we do flash renumber customers as needed.”
> Not sure if you understood my example:
> 1. DHCP customer needs to be moved to a different router.
> 2. Because customer will be moved to a different router, customer
> *will* be down for some time.
> 3. Moving the customer is done as a planned activity, at night, with
> alert to the customer several days in advance, in order to minimize
> customer inconvenience.

Well, consider this optional (but less convenient) approach:

Customers moving to other routers are generally groups of customers. (e.g. CMTS splits, etc.)

In such a case, creating a new prefix for that class of customers and advertising it to them several days in advance as well as shortening the preferred and valid lifetimes on the old prefix at that same time could be done.

The new prefix would then move with the customers.

This is inconvenient, but achievable. If you then wanted to migrate the customers to the prefix associated with the new router instead of making the transition prefix permanent, you could use short preferred and valid lifetimes on the transition prefix and start expiring it once the move was completed and the new permanent prefix had been advertised to them.

> Also, not directly related to the above: Business customers can also
> choose static addresses. If such a customer needs to be moved to a
> new router, addresses are also moved.


> I fail to see how this can be described as "we value our convenience
> above the impact this has on our customers". But I'll stop here.

See above.