Re: [spring] Beyond SRv6.

[Robert Raszuk <[e-mail]>]

> Are uSID values going to be entirely pseudo-random?

I see no reason why not ...

Networks are managed by some form of NMS. NMS can generate such values and
abstract it with a "node_name_usid" string for any additional processing
and human abstraction.

If that is the only concern I think we are done then. The only issue is
that if you happen to have hierarchical IGP you will not be able to
summarize them - but I don't think that this would be a showstopper to any
deployment.

Best,
R.





On Mon, Sep 2, 2019 at 12:24 PM Mark Smith <[e-mail]> wrote:

>
>
> 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.
>>
>>