Re: BGP Hijack/Sickness with AS4637

[Chris Conn <CConn () b2b2c com>]

Hello,

I am the contact for AS16532.

We never announced nor are we currently advertising this prefix as we are not a transit AS for anyone.  As well, it 
seems to appear and disappear from AS63956 looking glass.  According to that LG, the route changed 6d ago, and is 
*still currently visible* at this very moment;

https://lg.coloau.com.au/

Command: show route 18.29.238.0 protocol bgp table vrf-international.inet.0 active-path

vrf-international.inet.0: 696764 destinations, 2288960 routes (696480 active, 0 holddown, 103994 hidden)
+ = Active Route, - = Last Active, * = Both

18.29.238.0/23     *[BGP/170] 6d 01:06:11, localpref 90, from 103.97.52.2
                      AS path: 4637 3257 29909 16532 16532 16532 16532 I, validation-state: unverified


AS16532 is not announcing this prefix.  We have a strict prefix-list that is applied to all sessions.  As well, AS29909 
is filtering us using our announced AS-SETS/RPSL to avoid us the ability to do anything dumb.  And lastly, our 
announcements are being filtered by AS3257 as we are required to provide them via LOA.

There is still something wrong somewhere that is injecting this path, anyone have a LG pointed to AS4637 seeing this 
prefix announced with AS16532 in the AS path?

I doubt that AS29909 bouncing its BGP session with AS3257 (GTT) would change anything, as I am not seeing this prefix 
in their route-server

public () route-server as3257 net-re0> show route 18.29.238.0 protocol bgp active-path

inet.0: 691667 destinations, 11752983 routes (691665 active, 1 holddown, 1 hidden)
+ = Active Route, - = Last Active, * = Both

18.29.0.0/16       *[BGP/170] 3w4d 11:42:33, MED 0, localpref 100, from 213.200.87.23
                      AS path: 3257 174 3 I, validation-state: unverified
                    > to 141.136.111.13 via xe-1/0/0.0

{master}
public () route-server as3257 net-re0>


{master}
public () route-server as3257 net-re0> show route 18.29.238.0 protocol bgp | find 16532

Pattern not found
{master}



So whatever is happening, its not at AS16532, AS29909 nor AS3257 that I can find.


Chris Conn
AS16532




-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Tom Paseka via NANOG
Sent: Friday, May 25, 2018 6:01 PM
To: Nikolas Geyer <nik () neko id au>
Cc: NANOG list <nanog () nanog org>
Subject: Re: BGP Hijack/Sickness with AS4637

This looks like a route that has been cached by some ISPs/routers even though a withdrawal has actually happened.

If you actually forward packets a long the path, you'll see its not following the AS Path suggested, instead the real 
route that it should be.
Bouncing your session with 4637 would likely clear this.

-Tom

On Fri, May 25, 2018 at 11:59 AM, Nikolas Geyer <nik () neko id au> wrote:

> Greetings!
>
> Actually, what you have provided below shows the exact opposite. It 
> shows ColoAU have received the route from 4637 who have received it 
> from 3257 who have received it from 29909 who have received it from
> 16532 who originated it. It infers nothing about who 16532 found the route to come from.
>
> It is evident that GTT are advertising that route to Telstra Global :)
>
> Regards,
> Nik.
>
> >         And I'm pretty sure AS3257 (GTT ) is in the same boat as us, 
> > as
> they're not the one advertising those routes to AS4637
> >     AS16532 found it to come from AS4637 as you can see from this 
> > ColoAU
> LG output below
> > ----- https://lg.coloau.com.au/
> >
> > vrf-international.inet.0: 696533 destinations, 2248101 routes
> > (696249
> active, 0 holddown, 103835 hidden)
> > + = Active Route, - = Last Active, * = Both
> >
> > 18.29.238.0/23     *[BGP/170] 1d 19:57:28, localpref 90, from
> 103.97.52.2
> >                       AS path: 4637 3257 29909 16532 16532 16532
> > 16532
> I, validation-state: unverified
> > --
> > -----
> > Alain Hebert                                ahebert () pubnix net
> > PubNIX Inc.
> > 50 boul. St-Charles
> > P.O. Box 26770     Beaconsfield, Quebec     H9W 6G7
> > Tel: 514-990-5911  http://www.pubnix.net    Fax: 514-990-9443