Re: [Idr] [bess] Type 1 RD for Pure IPv6 network -- EVPN

Hi Gyan,

Please see inline..
Regards,
Muthu

On Sat, Jan 30, 2021 at 3:26 AM Gyan Mishra <hayabusagsm@gmail.com> wrote:

> Muthu
>
> How does RFa. 6286 AS wide BGP identifier change the BGP path selection
> process when all attributes are equal and ‘bestpath compare-routerid” is
> uses so the valid/best path is deterministic and oldest versus newest
> default.
>
The AS wide BGP identifier shouldn't change the BGP path selection process
in this case, since you compare by converting them to host byte order and
treating them as 4-octet unsigned integers as per RFC4271.

>
>
> I believe the BGP Identifier just as with OSPF or ISIS does not have to be
> routable, so in an IPv6 only network precluding RFC 6286 I believe could
> you still use a 4 octet IP address as the router-id.
>

Right. However, if we preclude RFC6286, then the BGP identifier needs to be
a valid unicast host IPv4 address (for e.g. can't be a multicast address):

<snip RFC4271>
   Syntactic correctness means that the BGP Identifier field represents
   a valid unicast IP host address.
</snip>

>
>
> This question comes up a lot these days as operations migrate to some
> flavor of IPv6 only core MPLS LDPv6, SR-MPLSv6, SRv6.
>
>
> Thanks
>
> Gyan
> On Wed, Jan 27, 2021 at 5:45 AM Muthu Arul Mozhi Perumal <
> muthu.arul@gmail.com> wrote:
>
>> Hi Tulasi,
>>
>> In pure IPv6 networks, I think using the BGP identifier in place of the
>> IP address part in the type 1 RD should suffice for all practical purposes.
>> The only catch is, if it is an AS-wide unique BGP identifier [RFC6286],
>> then it is not an IP address 'per se'. But, I think it makes no difference
>> from an interoperability standpoint..
>>
>> Perhaps, in line with RFC6286, we should redefine the IP address part of
>> the type 1 RD as just a 4-octet, unsigned, non-zero integer..
>>
>> Regards,
>> Muthu
>>
>> On Fri, Jan 22, 2021 at 11:31 AM TULASI RAM REDDY <
>> tulasiramireddy@gmail.com> wrote:
>>
>>> Hi All,
>>>
>>> In a pure IPv6 network, how do one expect to construct the Type 1 RD.
>>> As per EVPN RFC 7432 for EAD per ES, it should be Type 1 RD, but if the
>>> loopback address is only IPv6 then what is the expectation here?
>>> Should we use BGP router ID(32bit) here?
>>>
>>> From RFC7432: EVPN
>>>
>>> 8.2.1 <https://tools.ietf.org/html/rfc7432#section-8.2.1>.  Constructing Ethernet A-D per Ethernet Segment Route
>>>
>>>    The Route Distinguisher (RD) MUST be a Type 1 RD [RFC4364 <https://tools.ietf.org/html/rfc4364>].  The
>>>    *value field comprises an IP address of the PE (typically, the
>>>    loopback address)* followed by a number unique to the PE.
>>>
>>>
>>> Thanks,
>>> TULASI RAMI REDDY N
>>> _______________________________________________
>>> BESS mailing list
>>> BESS@ietf.org
>>> https://www.ietf.org/mailman/listinfo/bess
>>>
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> --
>
> <http://www.verizon.com/>
>
> *Gyan Mishra*
>
> *Network Solutions A**rchitect *
>
>
>
> *M 301 502-134713101 Columbia Pike *Silver Spring, MD
>
>