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

[Gyan Mishra <[e-mail]>]

I was thinking a CLI knob but RFC 6286 updates RFC 4271 which sounds like
new default behavior change with a upgrade.

Kind Regards

Gyan

On Thu, Feb 4, 2021 at 11:16 AM Jakob Heitz (jheitz) <[e-mail]>
wrote:

> There's no knob for RFC 6286. RID cannot be assumed to be unique across
> ASes. Period. Well, unless you have control over all the ASes. What do you
> mean by the knob exactly?
>
> Regards,
> Jakob.
>
>
> On Feb 4, 2021, at 6:55 AM, Gyan Mishra <[e-mail]> wrote:
>
> 
>
>
> Hi Acee
>
> Understood the uniqueness by ASN,RID per RFC 6286 AS wide BGP identifier
> for the IPv6 only SRv6 core use case.
>
> What I am uncomfortable as an operator with is the AS wide BGP identifier
> on every core router using the RFC 6286 knob for the SRv6 use case.  If we
> could continue to use unique IPv4 address  on every core router in the SRv6
> IPv6 only core use case I would be more comfortable then using the RFC 6286
> knob.
>
> Kind Regards
>
> Gyan
>
> On Thu, Feb 4, 2021 at 6:09 AM Acee Lindem (acee) <[e-mail]> wrote:
>
>> Hi Gyan,
>>
>> Agree with Jakob. There is no reason for the BGP Identifier to be a
>> unique IPv4 address. Consider an IPv6 only AS. However, there is nothing
>> precluding you from using an IPv4 address if you are uncomfortable.
>>
>>
>>
>> Thanks,
>> Acee
>>
>>
>>
>> *From: *BESS <[e-mail]> on behalf of "Jakob Heitz (jheitz)"
>> <jheitz=[e-mail]>
>> *Date: *Thursday, February 4, 2021 at 12:52 AM
>> *To: *Gyan Mishra <[e-mail]>
>>
>> *Cc: *TULASI RAM REDDY <[e-mail]>, Muthu Arul Mozhi
>> Perumal <[e-mail]>, "[e-mail]" <[e-mail]>, IDR
>> List <[e-mail]>
>> *Subject: *Re: [bess] [Idr] Type 1 RD for Pure IPv6 network -- EVPN
>>
>>
>>
>> RFC 6286 already updates RFC 4271.
>>
>> Basically, RID is not unique. (ASN,RID) is unique. The only limitation on
>> RID is that RID != 0.
>>
>>
>>
>> Regards,
>>
>> Jakob.
>>
>>
>>
>> *From:* Gyan Mishra <[e-mail]>
>> *Sent:* Wednesday, February 3, 2021 9:42 PM
>> *To:* Jakob Heitz (jheitz) <[e-mail]>
>> *Cc:* Muthu Arul Mozhi Perumal <[e-mail]>; TULASI RAM REDDY <
>> [e-mail]>; [e-mail]; [e-mail]
>> *Subject:* Re: [Idr] [bess] Type 1 RD for Pure IPv6 network -- EVPN
>>
>>
>>
>>
>>
>>
>>
>> On Wed, Feb 3, 2021 at 11:22 PM Jakob Heitz (jheitz) <[e-mail]>
>> wrote:
>>
>> <snip RFC4271>
>>
>>    Syntactic correctness means that the BGP Identifier field represents
>>    a valid unicast IP host address.
>>
>> </snip>
>>
>>
>>
>>      Gyan> I do see that verbiage in section 6.2
>>
>>
>>
>>    If the BGP Identifier field of the OPEN message is syntactically
>>
>>    incorrect, then the Error Subcode MUST be set to Bad BGP Identifier.
>>
>>    Syntactic correctness means that the BGP Identifier field represents
>>
>>    a valid unicast IP host address.
>>
>>
>>
>> BGP with IGP call back NH tracker checks the NH but how does BGP code validate the RIB that the router-id is a connected loopback but
>>
>> and also advertised by IGP.  I have not tried it but if you set a bogus router-id would all the BGP peers go down.
>>
>> I will try that in the lab.
>>
>>
>>
>> IOS-XR does not have this check. Nothing breaks by violating this rule.
>> IOS-XR implements RFC 6286.
>>
>> I think you'll be hard pressed to find a router that checks this.
>>
>>  Gyan> Agreed.  That is exactly what I thought.  I was going to try on
>> IOS XR but you saved me some time and results as I expected.  I will try
>> test RFC 6286 on XR.  Have you tried doing IPv6 only peers on XR and with
>> BGP identifier set unique to 4 octet IP address and see if that works.  I
>> am guessing it would work as XR does not have the check.
>>
>>
>>
>>     I  am not crazy about the RFC 6286 AS wide BGP identifier with 4
>> octet unsigned non zero integer.  Most operators are more comfortable
>> having unique 4 octet IP address as BGP identifier and I think would much
>> rather do that as long as the check does not exist as even with enabling
>> RFC 6286 and having AS wide unique identifier seems odd and scary to me as
>> normally the BGP identifier must always be unique within the domain or
>> breaks BGP.
>>
>>
>>
>> dual stack edge over v6 core RFC 5565 is becoming more common for
>> operators every day with SRv6 push and thus IPv6 only routers and running
>> into this issue where now you have to enable RFC 6286.
>>
>>
>>
>> I am thinking it maybe well worthwhile to write a draft that updates RFC
>> 4271 check as vendors don’t follow it anyway and as we all know not
>> checking is not going to break anything and making so that for IPv6 only
>> routers such as in a SRv6 core that the BGP identifier can remain a 4 octet
>> IP and then operators now could keep the same unique BGP identifier IP you
>> had on the router before you ripped it out of the core when transitioned to
>> SRv6.
>>
>> Regards,
>>
>> Jakob.
>>
>>
>>
>> --
>>
>> [image: Image removed by sender.] <http://www.verizon.com/>
>>
>> *Gyan Mishra*
>>
>> *Network Solutions Architect *
>>
>>
>>
>> *M 301 502-1347 13101 Columbia Pike
>> <https://www.google.com/maps/search/13101+Columbia+Pike?entry=gmail&source=g>
>> *Silver Spring, MD
>>
>>
>>
> --
>
> <http://www.verizon.com/>
>
> *Gyan Mishra*
>
> *Network Solutions A**rchitect *
>
>
>
> *M 301 502-1347 13101 Columbia Pike
> <https://www.google.com/maps/search/13101+Columbia+Pike?entry=gmail&source=g>
> *Silver Spring, MD
>
> --

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD