Re: [Lsr] Adam Roach's No Objection on draft-ietf-isis-segment-routing-extensions-24: (with COMMENT)

[Adam Roach <[e-mail]>]

On 5/15/19 12:22 AM, Les Ginsberg (ginsberg) wrote:
>
>> ---------------------------------------------------------------------------
>>
>> §2.4.6:
>>
>>>   10.1.1/24, Prefix-SID: Index 51
>>>   10.1.2/24, Prefix-SID: Index 52
>>>   10.1.3/24, Prefix-SID: Index 53
>>>   10.1.4/24, Prefix-SID: Index 54
>>>   10.1.5/24, Prefix-SID: Index 55
>>>   10.1.6/24, Prefix-SID: Index 56
>>>   10.1.7/24, Prefix-SID: Index 57
>> Please change these addresses to ranges reserved by IANA for
>> documentation purposes rather than those reserved for private use.
>>
> [Les:] Sorry, but this is not possible. :-)
> Example 2 is trying to show:
>
> 1)What the TLV encoding looks like when the prefix length is /24 or less. In such a case all four bytes of the prefix are not included in the encoded address - only the number of bytes necessary to fully specify the significant bits of the prefix are encoded.
> 2)With a range greater than 1, what is the prefix to SID mappings which result from the advertisement.
>
> This necessitates showing that it is the usable bits of the prefix that are incremented when mapping to the next SID in the range - in this example adding "0.0.1.0" to the prefix.
> RFC 5737 only reserves three disjoint /24 ranges - so this example cannot be supported using just the reserved addresses.


Oh, of course! Thanks for explaining that.

/a