Re: [Sidrops] [GROW] Deprecation of AS_SET and AS_CONFED_SET -- feedback requested

[Warren Kumari <[e-mail]>]

On Wed, Sep 25, 2019 at 11:32 PM Sriram, Kotikalapudi (Fed)
<[e-mail]> wrote:
>
> Jared,
>
> >(Obviously my search in e-mail today went afoul, I see it’s adopted..
>
> Yes, the draft was adopted. You can see the discussion here:
> https://mailarchive.ietf.org/arch/browse/idr/?gbt=1&q=WG%20adoption%20for%20draft-kumari-deprecate-as-set-confed-set
>
> One key point of the discussion was about the specification for action at
> a receiver when an update with AS_SET or AS_CONFED_SET is received.
> The consensus seemed to be: treat as Withdraw.
> We'll soon update the draft to add that.
>
> You had observed in that thread:
> >We should also (in parallel) reach out to some of the networks
> >still using as_sets that are visible in the global BGP table.
>
> How do we do this? On NANOG, RIPE, etc. lists? Please advise.
>
> >I did notice after this a few more BGP announcements with AS_SET
> >occurring on a very regular basis.  I suspect someone is doing some
> >research on it, perhaps someone reading this e-mail :-)
>
> The percentage of updates with AS_SET is observed to be about 0.05%.
> This has been in that ballpark for a long time.
> Are you computing the percentages in what you observe?
> Is it much different from 0.05%?
>
> Some recent measurements we have at NIST about this are as follow:
> (thanks to Lilia Hannachi - my colleague)
>

This is nice, but what would make it more useful would be if it also
reported if there are *useful* AS_SETS / if the AS_SET means anything.

For example, from Jared's email below:
AS path:  14061 3356 6762 23487 27738 27738 27738 27738 27738 27738
{27738} -- the 27738 AS already shows up as a non-AS_SET in the path.

I've also seen a number of instances where the AS_SET contains many
repeated instances, e.g:
AS path: 6939 3356 42020 39010 {39275 39275 39275 39275 39275 39275
39275 39275 39275 39275} -- this doesn't seem to actually mean
anything...

Looking at the top few AS paths with AS_SETs I see:
  28 12127
  27 27738
  24 11139
  17 23383
  13 12849

AS12127 - Telefonica Moviles El Salvador S.A. de C.V., SV (these are
all behind AS263783 - Telefonica Moviles El Salvador S.A. de C.V., SV
)
AS27738 - Ecuadortelecom S.A., EC
AS11139 - CWC-ROC-11139 - Cable & Wireless Dominica, DM
AS23383 - METRORED S.A. DE C.V., HN   (this also seems to provide
transit to AS267737? (advertising 45.168.172.0/24))
AS12849 HOTNET-IL AMS-IX Admin LAN, IL

W




> ******* OREGON3 Collector (20190827.00) **************
> August 27, 2019
>
> IPV4 : {normal=16540660, AGGREGATOR=1718902, ATOMIC_AGGREGATE=1086313, AS_CONFED_SET=0, AS_SET=8971, AS_CONFED_SEQUENCE=0}
> IPV4 Total 18323517
> IPV4 Percentage
> normal : 90.27%
> AGGREGATOR : 9.38%
> ATOMIC_AGGREGATE : 5.93%
> AS_CONFED_SET : 0.0%
> AS_SET : 0.05%
> AS_CONFED_SEQUENCE : 0.0%
> Number of ASs in the AS_SET Paths (IPV4) {1=7837, 2=876, 3=144, 4=50, 5=53, 6=2, 7=9}
> Position of AS_SET (IPV4) {Beginning=8971, Middle=0, Left_Most=0}
> Number of AS_SET with Reserver ASes (IPV4) 248
> Number of no-export and no-advertise (IPV4) {no-export=0, no-advertise=751278}
> no-export : 0.0%
> no-advertise : 4.95%
> ---------------------------------------------------------------
> IPV6 : {normal=67633, AGGREGATOR=8297, ATOMIC_AGGREGATE=3548, AS_CONFED_SET=0, AS_SET=36, AS_CONFED_SEQUENCE=0}
> IPV6 Total 76128
> IPV6 Percentage
> normal : 88.84%
> AGGREGATOR : 10.9%
> ATOMIC_AGGREGATE : 4.66%
> AS_CONFED_SET : 0.0%
> AS_SET : 0.05%
> AS_CONFED_SEQUENCE : 0.0%
> Number of ASs in the AS_SET Paths (IPV6) {1=24, 2=8, 3=1, 4=2, 8=1}
> Position of AS_SET (IPV6) {Beginning=36, Middle=0, Left_Most=0}
> Number of AS_SET with Reserver ASes (IPV6) 0
> Number of no-export and no-advertise (IPV6) {no-export=0, no-advertise=3765}
> no-export : 0.0%
> no-advertise : 4.95%
> ---------------------------------------------------------------------------
>
> ******* LINX Collector (20190827.00) **************
> August 27, 2019
>
> IPV4 : {normal=21697743, AGGREGATOR=2255396, ATOMIC_AGGREGATE=1425305, AS_CONFED_SET=0, AS_SET=11353, AS_CONFED_SEQUENCE=0}
> IPV4 Total 24036253
> IPV4 Percentage
> normal : 90.27%
> AGGREGATOR : 9.38%
> ATOMIC_AGGREGATE : 5.93%
> AS_CONFED_SET : 0.0%
> AS_SET : 0.05%
> AS_CONFED_SEQUENCE : 0.0%
> Number of ASs in the AS_SET Paths (IPV4) {1=9890, 2=1130, 3=188, 4=64, 5=65, 6=2, 7=14}
> Position of AS_SET (IPV4) {Beginning=11353, Middle=0, Left_Most=0}
> Number of AS_SET with Reserver ASes (IPV4) 348
> Number of no-export and no-advertise (IPV4) {no-export=6, no-advertise=0}
> no-export : 0.0%
> no-advertise : 0.0%
> *********************************
> IPV6 : {normal=69177, AGGREGATOR=8335, ATOMIC_AGGREGATE=3543, AS_CONFED_SET=0, AS_SET=37, AS_CONFED_SEQUENCE=0}
> IPV6 Total 77712
> IPV6 Percentage
> normal : 89.02%
> AGGREGATOR : 10.73%
> ATOMIC_AGGREGATE : 4.56%
> AS_CONFED_SET : 0.0%
> AS_SET : 0.05%
> AS_CONFED_SEQUENCE : 0.0%
> Number of ASs in the AS_SET Paths (IPV6) {1=24, 2=9, 3=1, 4=2, 8=1}
> Position of AS_SET (IPV6) {Beginning=37, Middle=0, Left_Most=0}
> Number of AS_SET with Reserver ASes (IPV6) 0
> Number of no-export and no-advertise (IPV6) {no-export=0, no-advertise=0}
> no-export : 0.0%
> no-advertise : 0.0%
>
> Sriram
>
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--
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