Re: A question about RFC5884

"Reshad Rahman (rrahman)" <rrahman@cisco.com> Sun, 16 July 2017 22:22 UTC

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From: "Reshad Rahman (rrahman)" <rrahman@cisco.com>
To: Mach Chen <mach.chen@huawei.com>, Ashesh Mishra <mishra.ashesh@outlook.com>
CC: "rtg-bfd@ietf.org" <rtg-bfd@ietf.org>
Subject: Re: A question about RFC5884
Thread-Topic: A question about RFC5884
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Date: Sun, 16 Jul 2017 22:21:58 +0000
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Hi,

My take too is that the RFC is pretty clear that Echo reply from egress
LSR is not mandatory.

Regards,
Reshad.



On 2017-07-16, 4:29 PM, "Rtg-bfd on behalf of Mach Chen"
<rtg-bfd-bounces@ietf.org on behalf of mach.chen@huawei.com> wrote:

>Hi Ashesh,
>
>Thanks for your prompt response, we're on the same page!
>
>Best regards,
>Mach
>
>> -----邮件原件-----
>> 发件人: Ashesh Mishra [mailto:mishra.ashesh@outlook.com]
>> 发送时间: 2017年7月16日 22:26
>> 收件人: Mach Chen
>> 抄送: rtg-bfd@ietf.org
>> 主题: Re: A question about RFC5884
>> 
>> That's how I read it ... assuming that proper handling of the LSR echo
>>includes
>> gracefully dropping it on rx.
>> 
>> Ashesh
>> 
>> On Jul 16, 2017, at 3:58 PM, Mach Chen <mach.chen@huawei.com> wrote:
>> 
>> Hi BFDers,
>> 
>> We met a multi-vendor interoperate issue recently, it's about whether
>>an Echo
>> reply is necessary.
>> 
>> In Section 6 of RFC5884, 2nd paragraph
>> 
>> "... The egress LSR MAY respond with an LSP Ping Echo
>>   reply message that carries the local discriminator assigned by it for
>>   the BFD session."
>> 
>> > From the above text, my understanding is that an Echo reply is
>>optional, the
>> egress LSR can freely to return or not return an Echo reply, and the
>>Ingress LSR
>> should not expect there MUST be an Echo reply, but if there is one, it
>>should
>> handle it properly.
>> 
>> Is my understanding correct?
>> 
>> Thanks,
>> Mach
>