Re: [dhcwg] DHCPv6 Failover -- LAST CHANCE

Tomek/Bernie,

Given this draft is in very much detailed and focused w/ HA design. I would
request if we can extend the WGLC for another date (21st). I have started
reading it and will be finishing mid of next week.

Thanks,
Yogendra Pal

On Mon, Sep 12, 2016 at 8:31 AM, tianxiang li <peter416733@gmail.com> wrote:

> Thank you for explaining this point. It does seem like the desirable
> method, and a /64 is sufficient enough for address allocation, so  I
> guess there's no need to address rebalancing.
>
> Thanks,
> Tianxiang
>
> 2016-09-08 21:09 GMT+08:00 perl-list <perl-list@network1.net>:
>
>>
>>
>> ------------------------------
>>
>> *From: *"tianxiang li" <peter416733@gmail.com>
>> *To: *"Kim Kinnear" <kkinnear@cisco.com>
>> *Cc: *"dhcwg" <dhcwg@ietf.org>
>> *Sent: *Wednesday, September 7, 2016 10:37:06 PM
>> *Subject: *Re: [dhcwg] DHCPv6 Failover -- LAST CHANCE
>>
>> 4.2.1 Independent allocation
>>
>>
>>
>> “In this allocation scheme, used for allocating individual IPv6
>> addresses, available IPv6 addresses are permanently (until server
>> configuration changes) split between servers…”
>>
>>
>>
>> If active-passive mode is used, it would mean that the addresses in the
>> secondary server would not be used unless the primary server fails. In that
>> case, wouldn’t permanently splitting the addresses between the primary and
>> secondary server a waste of addresses?
>>
>>
>>
>> If the address pool in the primary server becomes scarce, wouldn’t a
>> rebalancing mechanism be useful?
>>
>>
>> I read this section as just a codifying of what we do now without
>> failover.  We put half the /64 on the "primary" and half on the
>> "secondary".  It provides for some enhanced behavior where clients won't
>> need to get a new address in the case of server failure as the remaining
>> server can renew addresses.  Also, you wouldn't need to do any math as the
>> server would arithmetically split in half for you any subnets that are
>> marked for this behavior.  If offered a choice in the future, I would
>> probably choose this method as it is the simplest.
>>
>> Also, this bit here: "It also assumes that the pool assigned to each
>> server will never deplete." negates your comment about addresses becoming
>> scarce.  It is highly recommended (by all articles and documentation that
>> I've seen) that all end networks be configured as /64 subnets.  There are
>> quite a lot of addresses in a /64.  More than are in the entire IPv4
>> address space, is my understanding.  It is unlikely that a /64 will
>> experience IP address scarcity.
>>
>
>
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