Re: [mpls] I-D Action: draft-andersson-mpls-open-dt-questions-00.txt

Loa Andersson <loa@pi.nu> Fri, 30 April 2021 07:21 UTC

To: Stewart Bryant <stewart.bryant@gmail.com>
Cc: mpls <mpls@ietf.org>
References: <161968317610.20664.11107844270215068679@ietfa.amsl.com> <EDE7FDFB-4063-443D-BB72-C13238D22235@gmail.com> <eb4936d1-f226-4695-ac42-fd4938233645@pi.nu> <509D508D-F5DB-4DE7-B1F4-65318D6D088D@gmail.com>
From: Loa Andersson <loa@pi.nu>
Message-ID: <e734d483-9ae3-4aa5-16a7-94124ba9c710@pi.nu>
Date: Fri, 30 Apr 2021 09:21:30 +0200
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Subject: Re: [mpls] I-D Action: draft-andersson-mpls-open-dt-questions-00.txt
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Stewart,

So we need a small updates of the IGPs, right?

/Loa

On 29/04/2021 15:55, Stewart Bryant wrote:
> Hi Loa
> 
> LDP really layers on an IGP in most practical networks and the IGP can flood this without missing a heartbeat.
> 
> - Stewart
> 
> 
>> On 29 Apr 2021, at 14:41, Loa Andersson <loa@pi.nu> wrote:
>>
>> Stewart,
>>
>> I was that concerned about the amount of data that needs to be flooded, but rather that the mechanisms we have is insufficient.
>>
>> In the LDP case an LSR informs its peers about capabilities, they are not flooded across the network
>>
>> RFC 5561
>>
>>    - Each LDP speaker is assumed to implement a set of enhancements,
>>      each of which has an associated capability.  At any time, a speaker
>>      may have none, one, or more of those enhancements "enabled".  When
>>      an enhancement is enabled, the speaker advertises the associated
>>      capability to its peers.  By advertising the capability to a peer,
>>      the speaker asserts that it shall perform the protocol actions
>>      specified for the associated enhancement.  For example, the actions
>>      may require the LDP speaker to receive and process enhancement-
>>      specific messages from its peer.  Unless the capability has been
>>      advertised, the speaker will not perform protocol actions specified
>>      for the corresponding enhancement.
>>
>> An LSR that initiates an LSP with a maximum scanning depth depth need to know this for every LSR along the LSP.
>>
>> /Loa
>>
>> On 29/04/2021 12:25, Stewart Bryant wrote:
>>> It is one additional capability field (no more than a byte) to flood and I find it hard to imagine that it would not scale.
>>
>> -- 
>>
>> Loa Andersson                        email: loa@pi.nu
>> Senior MPLS Expert                          loa.pi.nu@gmail.com
>> Bronze Dragon Consulting             phone: +46 739 81 21 64
> 

-- 

Loa Andersson                        email: loa@pi.nu
Senior MPLS Expert                          loa.pi.nu@gmail.com
Bronze Dragon Consulting             phone: +46 739 81 21 64

Re: [mpls] I-D Action: draft-andersson-mpls-open-… Stewart Bryant
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Loa Andersson
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Stewart Bryant
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Loa Andersson
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Toerless Eckert
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Stewart Bryant
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Toerless Eckert
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Jeff Tantsura
Re: [mpls] I-D Action: draft-andersson-mpls-open-… Sergey Fomin