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Re: Verizon no BGP route to some of AS38365 (182.61.200.0/24)

From: Tom Beecher <beecher () beecher cc>
Date: Thu, 21 Jul 2022 12:34:36 -0400

Also looking at routeviews, there's ample evidence that Verizon and China
Telecom peer, so the question is, does China Telecom not advertise these
routes to Verizon, or is Verizon rejecting them for some reason?  I
suspect only engineers at CT and VZ can answer that.



I took a quick look this morning from our view at all prefixes we see with
an origin of AS38365.

- Some prefixes I see via multiple upstreams, and for those, CT (AS4134)
adds a +4 prepend via 701, but does not prepend anything else.
- Other prefixes I see via multiple upstreams , with no 701 path at all.

This would appear, at least externally, to be an intentional CT or Baidu
decision.

On Thu, Jul 21, 2022 at 12:21 PM Jon Lewis <jlewis () lewis org> wrote:


I looked at this a little last night, but didn't have time to write an
email about it.  Verizon has a lookingglass:

https://www.verizon.com/business/why-verizon/looking-glass/

which you can use to see that Verizon has no route covering 182.61.200.0.
Looking at routeviews, I see routes for 182.61.200.0/22,
and 182.61.200.0/21, but no path via Verizon.

Also looking at routeviews, there's ample evidence that Verizon and China
Telecom peer, so the question is, does China Telecom not advertise these
routes to Verizon, or is Verizon rejecting them for some reason?  I
suspect only engineers at CT and VZ can answer that.

On Wed, 20 Jul 2022, holow29 wrote:


To follow up on this:I've engaged Verizon's executive office to finally

try to get to a network engineer (because I don't have a contact myself).
The (proxied) response

from the engineer was that they aren't receiving any announcements for

these routes to AS701, and I would need to take it up with Baidu. I guess I
would like to understand

if that seems reasonable to people since it is my presumption that Baidu

would return and say something similar (that they advertise their routes to
their peers correctly

and to take it up with Verizon). To me, it seems like there is clearly a

failing in one of Verizon's peers where they are not advertising or
accepting this route

correctly, but that it would be incumbent on Verizon to do the legwork

to fix it since they are the ones who know their peering agreements and
have these contacts.

Unfortunately it seems like policy that Verizon pushes any issues that

aren't internal routing issues to an external party, but surely they have a
responsibility to

maintain their peering and routes to external services as well. In other

words, this type of buckpassing does not seem right to me (and I've heard
it from them on other

routing issues before), especially given that they are the ones

empowered to fix it. Any thoughts?


(As it happens, pan.baidu.com now resolves to an IP range that is

routable by Verizon, but it could always revert, and it seems like Verizon
should have these routes

regardless.)

Thanks.

On Fri, Jun 24, 2022 at 7:41 AM Matthew Huff <mhuff () ox com> wrote:

      From my limited vantage point it appears that there is some issue

between Verizon & Baidu. Baidu has 182.61.0.0/16 registered, but is only
advertising pieces

      of it globally (or at least from what I can see). In our tables,we

are receiving none from Verizon of  the subnets that are advertised
directly from Baidu

      (origin AS of 38365). The few within that registered range that

have a different origin AS are coming to us from Verizon. For example:




      *>   182.61.0.0/19    144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.0.0/18    144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.32.0/19   144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.64.0/18   204.148.121.221                        0

701 6453 55967 i


      *    182.61.128.0/23  204.148.121.221                        0

701 4134 4134 4134 4134 4134 58540 ?


      *>   182.61.130.0/24  144.121.203.141                        0

46887 6461 4134 23724 38365 38365 38365 i


      *>   182.61.130.0/23  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.131.0/24  144.121.203.141                        0

46887 6461 4134 23724 38365 38365 38365 i


      *>   182.61.132.0/23  144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.132.0/22  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.134.0/23  144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.136.0/22  144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.136.0/21  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.140.0/22  144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.144.0/21  144.121.203.141                        0

46887 3356 4134 58466 38365 i


      *>   182.61.144.0/20  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.160.0/19  204.148.121.221                        0

701 6453 55967 i


      *>   182.61.192.0/23  144.121.203.141                        0

46887 3356 4134 58540 i


      *>   182.61.194.0/23  144.121.203.141                        0

46887 3356 4134 58540 i


      *>   182.61.200.0/22  144.121.203.141                        0

46887 6461 4134 23724 38365 i


      *>   182.61.200.0/21  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.216.0/21  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.223.0/24  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i


      *>   182.61.224.0/19  144.121.203.141                        0

46887 6461 4134 58466 38365 38365 i




      We are getting the 182.61.200.0/21 and 182.61.200.0/22 from all

of our other peers:




      asr-inet2#sh ip bgp 182.61.200.0/21

      BGP routing table entry for 182.61.200.0/21, version 15779018

      Paths: (2 available, best #2, table default)

        Advertised to update-groups:

           3

        Refresh Epoch 1

        54004 6128 1299 4134 58466 38365 38365, (aggregated by 38365

119.75.208.225)


          148.77.99.201 from 148.77.99.201 (24.157.4.25)

            Origin IGP, localpref 100, valid, external, atomic-aggregate

            rx pathid: 0, tx pathid: 0

            Updated on Apr 29 2022 21:02:05 EDT

        Refresh Epoch 1

        46887 6461 4134 58466 38365 38365, (aggregated by 38365

119.75.208.225)


          129.77.17.254 from 129.77.17.254 (129.77.40.7)

            Origin IGP, metric 0, localpref 100, valid, internal,

atomic-aggregate, best


            rx pathid: 0, tx pathid: 0x0

            Updated on May 3 2022 04:02:50 EDT





      From: NANOG <nanog-bounces+mhuff=ox.com () nanog org> On Behalf Of

holow29

      Sent: Thursday, June 23, 2022 5:49 PM
      To: nanog () nanog org
      Subject: Verizon no BGP route to some of AS38365 (182.61.200.0/24)



      I've been trying (to no avail) for over a month now to get Verizon

to investigate their lack of BGP routing to 182.61.200.0/24, which hosts
Baidu Wangpan at

      pan.baidu.com (Baidu's cloud services/equivalent of Google Drive).



Easily verified through Verizon's Looking Glass.



We all know Verizon's BGP routing is a disaster, but does anyone have

any ideas?






----------------------------------------------------------------------
  Jon Lewis, MCP :)           |  I route
  StackPath, Sr. Neteng       |  therefore you are
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
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