Hi Sasha,






When a MAC-VRF use a type 1 RD,  is it expected that the RD of the EVPN 
Instance has differnet RD on different PE? When a MAC-VRF use a type 2 RD,  is 
it expected that the RD of the EVPN Instance has the same RD on different PE?


In many deployment, whether the RD of the EVPN Instance has different RD-value 
on different PE is independent of the RD-type.


The RD of A-D per ES route is limited to type 1 RD just because orther RD-types 
are assumed that they will have the same value for a specified EVI on different 
PEs.


Is my understanding correct?






Another way is constructing each A-D per ES route separately by using the RD of 
corresponding MAC-VRF, as described in 
draft-rabadan-bess-evpn-inter-domain-opt-b.






Thanks,


Yubao















原始邮件



发件人:AlexanderVainshtein
收件人:王玉保10045807;
抄送人:draft-rabadan-bess-evpn-inter-domain-op...@ietf.org;rfc7432...@ietf.org;bess@ietf.org;jorge.raba...@nokia.com;
日 期 :2023年05月15日 21:24
主 题 :RE: [EXTERNAL] Re:[EXTERNAL] Re: [bess] Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b




Hi Yubao,


Can you please clarify what you mean by “another way to construct A-D per ES 
route has been in sight”?


 


From my POV using Type 1 RDs in all types of EVPN routes has multiple 
advantages – starting from the fact that it prevents RRs suppressing routes 
advertised by different PEs as part of the BGP path selection process. (The 
same actually applies for VPN-IP routes as well). IMHO and FWIW the operators 
should be discouraged from using other RD types even when it is not already 
prohibited.


The bottom line: For the record I strongly oppose the proposal to relax the 
limitation on RDs in EVPN per ES Ethernet A- (Type 1) routes that exists from 
the -00 revision of the EVPN draft.  


 


Regards,


Sasha


 



From: wang.yub...@zte.com.cn <wang.yub...@zte.com.cn> 
 Sent: Monday, May 15, 2023 3:56 PM
 To: Alexander Vainshtein <alexander.vainsht...@rbbn.com>
 Cc: draft-rabadan-bess-evpn-inter-domain-op...@ietf.org; rfc7432...@ietf.org; 
bess@ietf.org; jorge.raba...@nokia.com
 Subject: [EXTERNAL] Re:[EXTERNAL] Re: [bess] Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b



 


 


Hi Sasha,


 


Thanks for your helpful notes.


There is only one method to determine the RD of A-D per ES routes in the 
original years of RFC7432, but now there are at least two methods to determine 
the RD of A-D per ES routes.


If it is the only reason why RFC7432 restrict the RD of A-D per ES route to 
type 1 RD, maybe it is a good chance for the restriction to be relaxed, because 
another way to construct A-D per ES route has been in sight.


The original way can still be “RECOMMENDED”while other ways don't have to be 
forbidden. Maybe we can say that it is out of the scope of rfc7432bis (but not 
forbidden).


 


If RFC7432 is not revised, people who decide not to assign Type 1 RDs to  
MAC-VRFs should bear the consequences in mind, including non-applicability of 
the solution suggested in Section 3.1.2 of the EVPN Inter-Domain Option B 
draft, as you point out in another mail. But when RFC7432 is revised and 
rfc7432bis is still a draft, I think it will be better to take new scenarios 
into account.


 


Especially on a RR node,  according to RFC7432 or current rfc7432bis, a RR has 
to discard the A-D per ES routes which don't have a type 1 RD, but a RR is not 
responsible for selecting different RD for different set of route-targets at 
all. A RR has no difficulty to permit a A-D per ES route with other RD-type to 
pass through, while it has to discard it according to current rfc7432bis. 


 


Thanks,


Yubao


 


 


原始邮件



发件人:AlexanderVainshtein



收件人:王玉保10045807;



抄送人:draft-rabadan-bess-evpn-inter-domain-op...@ietf.org;rfc7432...@ietf.org;bess@ietf.org;jorge.raba...@nokia.com;



日 期 :2023年05月15日 16:09



主 题 :RE: [EXTERNAL] Re: [bess] Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b




Yubao,


Please note that an EVPN PE that s attached to a MH ES, generally speaking, has 
to generate multiple per-ES A-D routes with the ESI of this MH ES in their NLRI.


This happens because:


·       The set of these routes, in its entirety, must carry the Route Targets 
of all the EVI that are local attached to this MH ES


·       The number of Route Targets that can be caried in a single BGP Update 
message is limited.


 


For BGP path selection process not to suppress some of these routes, these 
routes in this set must include different RDs in their NLRI.


Since the set of these routes changes dynamically as new EVIs are attached 
to/detached from the MS EH in question, these RDs have to be auto-generated by 
the PE itself.


This, in its turn requires usage of Type 1 RDs because these can be 
auto-generated by the PEs while remaining globally unique.


 


The bottom line: Restriction of RDs used in the NLRI of per-ES Ethernet A-D 
routes cannot be relaxed.


 


Hope this helps.


 


Regards,


Sasha


 



From: BESS <bess-boun...@ietf.org> On Behalf Of wang.yub...@zte.com.cn
 Sent: Monday, May 15, 2023 10:40 AM
 To: jorge.raba...@nokia.com
 Cc: draft-rabadan-bess-evpn-inter-domain-op...@ietf.org; rfc7432...@ietf.org; 
bess@ietf.org
 Subject: [EXTERNAL] Re: [bess] Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b



 


 


Hi Jorge,


 


I think the description in draft-rabadan-bess-evpn-inter-domain-opt-b is OK. 
But I don't know why the RD of AD per ES route is limited to type 1 RD. That's 
why I talk about this together with rfc7432bis.


If the scenario from draft-rabadan-bess-evpn-inter-domain-opt-b has shown out 
that it will be useful for the RD-type of AD per ES route being consistence 
with MAC-VRF RD, I think maybe it is not necessary for rfc7432bis to keep these 
restraints unchanged. I notice that you are also a co-author of rfc7432bis, how 
do you think from the viewpoint of rfc7432bis? 


 


Thanks,


Yubao


 


 


原始邮件



发件人:JorgeRabadan(Nokia)



收件人:王玉保10045807;draft-rabadan-bess-evpn-inter-domain-op...@ietf.org;rfc7432...@ietf.org;



抄送人:bess@ietf.org;



日 期 :2023年05月13日 00:23



主 题 :Re: Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b  




Hi Yubao,


 


Thanks for reviewing the document.


I don’t see any conflicting information:


 


1.       On one hand the use of type 1 RD for MAC-VRF is RECOMMENDED in 
rfc7432bis, which means that normally people will have a type 1 RD in MAC-VRFs. 
If you don’t follow that strong recommendation for the MAC-VRF RD, you can’t 
use the documented solutions in 3.1.2 or 3.1.3


2.       On the other hand draft-rabadan-bess-evpn-inter-domain-opt-b is 
documenting some existing solutions, but not specifying or imposing any in 
particular.


 


So I don’t think there is conflicting information. But if you still think we 
should clarify that in draft-rabadan-bess-evpn-inter-domain-opt-b we’ll be 
happy to do it.


 


Thanks.


Jorge


 



From: wang.yub...@zte.com.cn <wang.yub...@zte.com.cn>
 Date: Friday, May 12, 2023 at 4:54 AM
 To: draft-rabadan-bess-evpn-inter-domain-op...@ietf.org 
<draft-rabadan-bess-evpn-inter-domain-op...@ietf.org>, Jorge Rabadan (Nokia) 
<jorge.raba...@nokia.com>, rfc7432...@ietf.org <rfc7432...@ietf.org>
 Cc: bess@ietf.org <bess@ietf.org>
 Subject: Discussion on rfc7432bis and 
draft-rabadan-bess-evpn-inter-domain-opt-b  



 


CAUTION: This is an external email. Please be very careful when clicking links 
or opening attachments. See the URL nok.it/ext for additional information.



 


 


Hi Authors,


 


It seems that draft-rabadan-bess-evpn-inter-domain-opt-b has conflicting 
discription with rfc7432 about the RD-type of AD per ES routes:


 


Section 3.1.3 of draft-rabadan-bess-evpn-inter-domain-opt-b-00:   "If that is 
the case, now the A-D per ES routes can use the route distinguisher assigned to 
the EVPN Instance (or VRF), which is the same one used by the routes type 2 or 
5 for the EVI."


Section 8.2.1 of rfc7432bis: "The Route Distinguisher MUST be a Type 1 RD 
[RFC4364].  The value field comprises an IP address of the PE (typically, the 
loopback address) followed by a number unique to the PE."


 


The RD of EVI is not always a Type 1 RD but rfc7432 says that the RD of AD per 
ES route MUST be a Type1 RD. If it is not necessary to prevent other RD-types 
from being used in AD per ES routes, is it better for rfc7432bis to change the 
"MUST" to "MAY" ?  I think such change is also compatible.


 


Thanks,


Yubao











 






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