In this specific event, 3356 not withdrawing routes is certainly a head scratcher, and I'm sure for many the thing we're most looking forward to a definitive answer on. However, if a network only has 3356 as their upstream, they are 100% at the mercy of 3356 at all times. Having a redundant AND diverse connection to a 2nd upstream ASN at least provides you some options. In this case for example, let's say at all times you did a +2 prepend to both 3356 and Acme. 3356 even happens, you shut down your session to them. Some percentage of your traffic that would have been faceplanting in/through 3356 now works via Acme. Then you notice the non-withdrawl issue. You can then remove 1 prepend, or perhaps deagg strategically to try and get more traffic away from the trouble. A redundant path to a different.upstream at least provides you some potential options to work around that with which you otherwise could not. It wouldn't be perfect, but options > no options. On Mon, Aug 31, 2020 at 5:08 PM Warren Kumari <warren@kumari.net> wrote:
On Mon, Aug 31, 2020 at 4:36 PM Tom Beecher <beecher@beecher.cc> wrote:
Hopefully those customers learned the difference between redundancy and
diversity this weekend. :)
I'm unclear how either solves things for many customers...
If they had CenturyLink and AcmeNetworkWidgets, and announce the same network through both -- and their connection to CL went down, *but CL continues to announce / doesn't withdraw* they are still stuck, yes? (Unless they can deaggregate that is...) What am I missing?
W
On Mon, Aug 31, 2020 at 3:48 PM Eric Kuhnke <eric.kuhnke@gmail.com>
There's a number of enterprise end user type customers of 3356 that
have on-premises server rooms/hosting for their stuff. And they spend a lot of money every month for a 'redundant' metro ethernet circuit that takes
On Mon, Aug 31, 2020 at 9:36 AM Drew Weaver <drew.weaver@thenap.com>
wrote:
I also found the part where they mention that a lot of hosting
companies only have one uplink to be quizzical and also the fact that he goes pretty close to implying that its Centurylink’s customers fault for not having multiple paths to Cloudflare that don’t touch Centurylink a bit
From: NANOG <nanog-bounces+drew.weaver=thenap.com@nanog.org> On
Behalf Of Tom Beecher
Sent: Monday, August 31, 2020 9:26 AM To: Hank Nussbacher <hank@interall.co.il> Cc: NANOG <nanog@nanog.org> Subject: Re: Centurylink having a bad morning?
https://blog.cloudflare.com/analysis-of-todays-centurylink-level-3-outage/
I definitely found Mr. Prince's writing about yesterday's events
fascinating.
Verizon makes a mistake with BGP filters that allows a secondary
mistake from leaked "optimizer" routes to propagate, and Mr. Prince takes every opportunity to lob large chunks of granite about how terrible they are.
L3 allows an erroneous flowspec announcement to cause massive global
connectivity issues, and Mr. Prince shrugs and says "Incidents happen."
On Mon, Aug 31, 2020 at 1:15 AM Hank Nussbacher <hank@interall.co.il>
wrote:
On 30/08/2020 20:08, Baldur Norddahl wrote:
https://blog.cloudflare.com/analysis-of-todays-centurylink-level-3-outage/
Sounds like Flowspec possibly blocking tcp/179 might be the cause.
But that is Cloudflare speculation.
Regards, Hank
Caveat: The views expressed above are solely my own and do not express
An outage is what it is. I am not worried about outages. We have
multiple transits to deal with that.
It is the keep announcing prefixes after withdrawal from peers and
customers that is the huge problem here. That is killing all the effort and money I put into having redundancy. It is sabotage of my network after I cut the ties. I do not want to be a customer at an outlet who has a system
But I disagree in that it would be impossible. They need to make a
good report telling exactly what went wrong and how they changed the design, so something like this can not happen again. The basic design of BGP is such that this should not happen easily if at all. They did something unwise. Did they make a route reflector based on a database or something?
Regards,
Baldur
On Sun, Aug 30, 2020 at 5:13 PM Mike Bolitho <mikebolitho@gmail.com>
wrote:
Exactly. And asking that they somehow prove this won't happen again is
impossible.
- Mike Bolitho
On Sun, Aug 30, 2020, 8:10 AM Drew Weaver <drew.weaver@thenap.com>
wrote:
I’m not defending them but I am sure it isn’t intentional.
From: NANOG <nanog-bounces+drew.weaver=thenap.com@nanog.org> On
Behalf Of Baldur Norddahl
Sent: Sunday, August 30, 2020 9:28 AM To: nanog@nanog.org Subject: Re: Centurylink having a bad morning?
How is that acceptable behaviour? I shall remember never to make a contract with these guys until they can prove that they won't advertise my
wrote: diverse fiber paths from their business park office building to the local clink/level3 POP. But all that last mile redundancy and fail over ability doesn't do much for them when 3356 breaks its network at the BGP level. puzzling. It could have just been poorly written. the views or opinions of my employer that will do that. Luckily we do not currently have a contract and now they will have to convince me it is safe for me to make a contract with them. If that is impossible I guess I won't be getting a contract with them. prefixes after I pull them. Under any circumstances.
søn. 30. aug. 2020 15.14 skrev Joseph Jenkins <
joe@breathe-underwater.com>:
Finally got through on their support line and spoke to level1. The
only thing the tech could say was it was an issue with BGP route reflectors and it started about 3am(pacific). They were still trying to isolate the issue. I've tried failing over my circuits and no go, the traffic just dies as L3 won't stop advertising my routes.
On Sun, Aug 30, 2020 at 5:21 AM Drew Weaver via NANOG <nanog@nanog.org>
wrote:
Hello,
Woke up this morning to a bunch of reports of issues with connectivity
had to shut down some Level3/CTL connections to get it to return to normal.
As of right now their support portal won’t load:
https://www.centurylink.com/business/login/
Just wondering what others are seeing.
-- I don't think the execution is relevant when it was obviously a bad idea in the first place. This is like putting rabid weasels in your pants, and later expressing regret at having chosen those particular rabid weasels and that pair of pants. ---maf