Re: [spring] Beyond SRv6.

[Mark Smith <[e-mail]>]

On Mon., 2 Sep. 2019, 17:58 Robert Raszuk, <[e-mail]> wrote:

> Hi Mark,
>
>
>> The uSID proposal is taking the position that all the bits after the high
>> order prefix are available for any purpose. This is not correct, and would
>> violate a number of standards track RFCs, including the IPv6 Addressing
>> Architecture RFC (RFC 4291) and the ULA RFC (RFC 4193).
>>
>> In particular, 40 bits of a ULA prefix, between /8 and /48, the Gobal ID,
>> must be pseudo random. This is the most critical property of ULA addresses
>> and prefixes, as it is the solution to the problem ULAs are designed to
>> solve.
>>
>
> RFC 4193 says about Global_ID allocation:
>
>    The local assignments are self-generated and do not need any central
>    coordination or assignment, but have an extremely high probability of
>    being unique.
>
>
Are uSID values going to be entirely pseudo-random?

"

3.2.1 <https://tools.ietf.org/html/rfc4193#section-3.2.1>.  Locally
Assigned Global IDs

   Locally assigned Global IDs MUST be generated with a pseudo-random
   algorithm consistent with [RANDOM
<https://tools.ietf.org/html/rfc4193#ref-RANDOM>]."



> So in some the case operator may choose to make such "local assignment" of
> Global ID to be per router not per network. And that is all what is needed
> for uSID. uSID address blocks does not need to be continues.
>
> It also does not contradict with any RFC does it ? What breaks if I use
> more then one self generated Global ID in my network ?
>
> Note that the above question goes way beyond any SR related discussion so
> perhaps deserves a separate 6man thread.
>
> Best,
> R.
>
>