Hi Sudeep,

I think when a new PE is brought up to a redundancy group, the related 
forwarding must be blocked.


Regards,

Patrice

   
[http://www.cisco.com/web/europe/images/email/signature/est2014/logo_06.png?ct=1406640631632]

Patrice Brissette
TECHNICAL LEADER.ENGINEERING

[email protected]<mailto:[email protected]>
Phone: +1 613 254 3336


Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE
Canada
Cisco.com<http://www.cisco.com/global/CA/>



[http://www.cisco.com/assets/swa/img/thinkbeforeyouprint.gif] Think before you 
print.

This email may contain confidential and privileged material for the sole use of 
the intended recipient. Any review, use, distribution or disclosure by others 
is strictly prohibited. If you are not the intended recipient (or authorized to 
receive for the recipient), please contact the sender by reply email and delete 
all copies of this message.

Please click 
here<http://www.cisco.com/web/about/doing_business/legal/cri/index.html> for 
Company Registration Information.




From: <[email protected]<mailto:[email protected]>> on behalf 
of sudeep g ggg <[email protected]<mailto:[email protected]>>
Date: Tuesday, November 24, 2015 at 12:20 AM
To: "Satya Mohanty (satyamoh)" <[email protected]<mailto:[email protected]>>
Cc: Patrice Brissette <[email protected]<mailto:[email protected]>>, 
"[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [bess] REG: draft-mohanty-bess-evpn-df-election-02

Respected Satya,

Let me thank you for the mail. IT is much appreciated. May I request you to 
look in to my reply named "sudhin". If this is already taken care my sincere 
apologies for asking redundant question.

Regards,
Sudhin Jacob


1. When a new PE comes in the MH segment.


[Satya] Yes, New PE needs to wait for 3 sec. According to RFC 7438, the 
receiving PEs also need to wait for 3 secs. But, ideally, a PE that is going 
from DF to non-DF or non-DF to non-DF should become the non-DF rightaway. Only 
the PE that is going DF really needs to wait for 3 secs. This is not explicitly 
spelled out in the draft but we are thinking along these lines.

Sudhin>> you are correct Satya but how to deal with traffic for 3 seconds when 
a new type 4 route comes. DF election kicks in and all PE's, For 3 seconds how 
to deal with traffic, the state machines need to be updated like blocking 
traffic or forwarding. if during that time the traffic is forwarded then a loop 
will be created. the EVPN RFC says SH label and BUM drop after the election, 
but correct me if I am totally wrong during the transition how to deal is not 
covered.I request your valid input on this. How to deal in that situation,what 
is the state of PE's during 3 seconds period.How to reach a consensus between 
vendors. Say for example vendors design custom solution to handle this, then 
how the inter op between vendors will not work.


Now, delay of BGP updates is not dependent on the above behavior. That depends 
on the network topology and queueing/processing at intermediate nodes.
With HRW, a PE coming up will result in minimal disruption of the established 
DF for various vlans (bundles) as opposed to RFC 7438 mod-based.



On Tue, 24 Nov 2015 08:55:20 +0530 "Satya Mohanty (satyamoh)" wrote
>




Hi Sudeep,



Please see inline [Satya].
Patrice, thanks for your observation.








From: BESS on behalf of "Patrice Brissette (pbrisset)"

Date: Monday, November 23, 2015 6:53 PM

To: sudeep g ggg , "[email protected]<mailto:[email protected]>"

Subject: Re: [bess] REG: draft-mohanty-bess-evpn-df-election-02










Sudeep,



Why do you think there will be a loop? Per ES EAD route carry ESI-mpls extcomm 
which has a split-horizon label to avoid such problem. I think also it depends 
on how your configure your router (in what order).
In the case of PBB-EVPN, it is taken care by the nature of PBB.










Regards,



Patrice















Patrice Brissette

TECHNICAL LEADER.ENGINEERING



[email protected]<mailto:[email protected]>

Phone: +1 613 254 3336





Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE

Canada

Cisco.com













Think before you print.



This email may contain confidential and privileged material for the sole use of 
the intended recipient. Any review, use, distribution or disclosure by others 
is strictly prohibited. If you are not the intended recipient (or authorized to 
receive for the
recipient), please contact the sender by reply email and delete all copies of 
this message.
Please
click here for Company Registration Information.



















From: BESS on behalf of sudeep g ggg

Date: Sunday, November 22, 2015 at 1:21 AM

To: "[email protected]<mailto:[email protected]>"

Subject: [bess] REG: draft-mohanty-bess-evpn-df-election-02







Respected Authors,



I am having 2 use cases based on that, I have a couple of queries. Correct me 
if I am wrong or If I am missing something.Your input is highly appreciating.



1. When a new PE comes in the MH segment.






[Satya] Yes, New PE needs to wait for 3 sec. According to RFC 7438, the 
receiving PEs also need to wait for 3 secs. But, ideally, a PE that is going 
from DF to non-DF or non-DF to non-DF should become the non-DF rightaway. Only 
the
PE that is going DF really needs to wait for 3 secs. This is not explicitly 
spelled out in the draft but we are thinking along these lines.



Now, delay of BGP updates is not dependent on the above behavior. That depends 
on the network topology and queueing/processing at intermediate nodes.
With HRW, a PE coming up will result in minimal disruption of the established 
DF for various vlans (bundles) as opposed to RFC 7438 mod-based.









2. When a PE is brought down due to MW(Maintenance window).






[Satya] As per the HRW, if this PE was not the DF for a vlan (vlan-bundle) this 
should have no effect on the DF election.
This is where it again performs better than the RFC 7438 modulo-based algorithm.
If this was the DF, then some other surviving PE, say PE' for which the 
Hash(PE', vlan) is maximum can become the PE right away on receiving the BGP 
withdraw.
There is no need for a three second wait.











As per the above use cases.There will be change in DF election process. And for 
3 seconds there is chance of transient loop.There is delay of bgp update 
received by each PE.Kindly let me know whether this is taken care.

Moreover 3 seconds if the traffic is blocked in the network creates problem for 
delay sensitive traffic like voice,images etc.



May I know about your views in above cases.



Regards,

Sudhin
















Get your own

FREE website,
FREE domain &
FREE mobile app with Company email.

Know
More >













[https://sigads.rediff.com/RealMedia/ads/adstream_nx.ads/www.rediffmail.com/signatureline.htm@Middle]<https://sigads.rediff.com/RealMedia/ads/click_nx.ads/www.rediffmail.com/signatureline.htm@Middle?>
Get your own FREE website, FREE domain & FREE mobile app with Company email.
        Know More 
><http://track.rediff.com/click?url=___http://businessemail.rediff.com?sc_cid=sign-1-10-13___&cmp=host&lnk=sign-1-10-13&nsrv1=host>
_______________________________________________
BESS mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/bess

Reply via email to