On 23/05/2025 10:10, Aijun Wang wrote:
Then, what’s the differences between the two statements:
first is for case when the prefix reachability is not regained after UPA
was generated.
Second is when the prefix reachability was regained before the UPA was
withdrawn. It basically says UPA must be withdrawn at the time the
prefix becomes reachable.
“UPA advertisements SHOULD therefore be withdrawn after some amount of
time, that would provides sufficient time for UPA to be flooded
network-wide and acted upon by receiving nodes, but limits the
presence of UPA in the network.”
And:
“ABR or ASBR MUST withdraw the previously advertised UPA when the
reason for which the UPA was generated was lost - e.g. prefix
reachability was restored or its metric has changed such that it does
not represent the protocol specific maximum prefix metric.”
Here, does “withdraw” just mean to “stop advertisement”?
yes.
Peter
If no, what’s the mechanism of second “withdraw”?
Best Regards
Aijun Wang
China Telecom
*发件人:*[email protected]
[mailto:[email protected]] *代表 *Peter Psenak
*发送时间:*2025年5月23日14:55
*收件人:*Aijun Wang <[email protected]>; [email protected]
*主题:*[Lsr] Re: 答复: I-D Action:
draft-ietf-lsr-igp-ureach-prefix-announce-06.txt
On 23/05/2025 03:32, Aijun Wang wrote:
Hi, All:
I must point out that the updated draft doesn't address previous
issues that described in [1].
Especially, the activation of flawed LSInfinity feature(there is
detail analysis for this flawed feature that is defined in OSPF 2328).
And, some updated contents will deteriorate the traffic pattern
within the network.
For example, It says: “ABR or ASBR MUST withdraw the previously
advertised UPA when the reason for which the UPA was generated was
lost”.
The above requirement will advertise the specific prefixes within
the network, which will weaken the original summary effect, and
attract the traffic via one or some of ABRs.
no, above is not true, the new text does not say to advertise
reachablity for a summarized prefix, it only talks about removing the
previously advertised UPA.
Please read carefully before commenting.
Peter
[1]: Reasons of abandoning UPA:
https://datatracker.ietf.org/doc/draft-wang-lsr-reasons-of-abandon-upa-proposal/
Best Regards
Aijun Wang
China Telecom
-----邮件原件-----
发件人: [email protected]
[mailto:[email protected]
<mailto:[email protected]>] 代表 [email protected]
发送时间: 2025年5月22日21:20
收件人: [email protected]
抄送: [email protected]
主题: [Lsr] I-D Action:
draft-ietf-lsr-igp-ureach-prefix-announce-06.txt
Internet-Draft draft-ietf-lsr-igp-ureach-prefix-announce-06.txt is
now available. It is a work item of the Link State Routing (LSR)
WG of the IETF.
Title: IGP Unreachable Prefix Announcement
Authors: Peter Psenak
Clarence Filsfils
Daniel Voyer
Shraddha Hegde
Gyan Mishra
Name: draft-ietf-lsr-igp-ureach-prefix-announce-06.txt
Pages: 14
Dates: 2025-05-22
Abstract:
In the presence of summarization, there is a need to signal loss of
reachability to an individual prefix covered by the summary. This
enables fast convergence by steering traffic away from the node
which
owns the prefix and is no longer reachable.
This document describes how to use the existing protocol mechanisms
in IS-IS and OSPF, together with the two new flags, to
advertise such
prefix reachability loss.
The IETF datatracker status page for this Internet-Draft is:
https://datatracker.ietf.org/doc/draft-ietf-lsr-igp-ureach-prefix-announce/
<https://datatracker.ietf.org/doc/draft-ietf-lsr-igp-ureach-prefix-announce/>
There is also an HTMLized version available at:
https://datatracker.ietf.org/doc/html/draft-ietf-lsr-igp-ureach-prefix-announce-06
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-igp-ureach-prefix-announce-06>
A diff from the previous version is available at:
https://author-tools.ietf.org/iddiff?url2=draft-ietf-lsr-igp-ureach-prefix-announce-06
<https://author-tools.ietf.org/iddiff?url2=draft-ietf-lsr-igp-ureach-prefix-announce-06>
Internet-Drafts are also available by rsync at:
rsync.ietf.org::internet-drafts
_______________________________________________
Lsr mailing list -- [email protected] <mailto:[email protected]>
To unsubscribe send an email to [email protected]
<mailto:[email protected]>
_______________________________________________
Lsr mailing list -- [email protected]
To unsubscribe send an email to [email protected]
