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

[TULASI RAM REDDY <[e-mail]>]

 Hi All,

So, we can also assume the below "IP address of the PE" requirement for
Type 1 RD of EAD per AS
is not true in pure IPv6 only AS.
This should be read as any AS wide unique 4-octet, unsigned, non-zero
integer (similar to RFC6286).

>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.

On Thu, Feb 4, 2021 at 4:39 PM 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  *Silver Spring, MD
>
>
>


-- 
TULASI RAMI REDDY N