Re: BGP Debug question (How to know what AS, neighbor is using

Hey team,

Sorry to drag this thread back up ... but I went through Marko's link and
then thought of the lab. I believe there is a calculator in the lab no?
Can it display scientific?

Funny thing, tonight I was thinking of this thread and also Marko's link
(thanks Marko)
http://cisco.markom.info/2008/10/peering-with-unknown-autonomous-system.html

In Marko's link, he mentions this error message:

%BGP-3-NOTIFICATION: sent to neighbor 192.168.12.2 2/2 (peer in wrong
AS) 2 bytes FDEA

When I first read that I was like ... what? I understand hex to dec to bin
etc ... but that number, FDEA, did not equal 65002 in my mind ;-)

I am good with hex up to a point but FDEA ... whoa. Thank God for
calculators! If you plug FDEA into the scientific calc, then click on dec
and it shows 65002.

Not sure if anyone else saw this, and most of you already figured it out ...
but I figured I would shared anyways ... HTH,

Andrew Lee Lissitz

On Wed, Aug 12, 2009 at 6:01 AM, <MDevarajan_at_inautix.co.in> wrote:

> There is a way to find out the correct AS..
>
> Copy the bytes value (0004) and put in calc in binary and click decimal ..
> the the value comes is the correct AS...
>
>
>
>
> Jul 11 00:18:42.815: %BGP-3-NOTIFICATION: sent to neighbor 100.100.24.4
> 2/2
> > (peer in wrong AS) 2 bytes 0004 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF
> 002D
> > 0104 0004 00B4 6464 1804 1002 0601 0400 0100 0102 0280 0002 0202 00
> >
>
> Please correct me if I am wrong.
>
> Thanks in advance,
> Mohan
>
>
>
>
>
>
> Marko Milivojevic <markom_at_markom.info>
> Sent by: nobody_at_groupstudy.com
> 08/10/2009 05:52 AM
> Please respond to
> Marko Milivojevic <markom_at_markom.info>
>
>
> To
> Joe Astorino <jastorino_at_ipexpert.com>
> cc
> Pradeep Malik <pradeepmlk_at_gmail.com>, Cisco certification
> <ccielab_at_groupstudy.com>
> Subject
> Re: BGP Debug question (How to know what AS, neighbor is using to peer
> with my IP ???????)
>
>
>
>
>
>
> Sometime ago I wrote a troubleshooting article on this subject that
> you may find useful. Get it here:
>
>
> http://cisco.markom.info/2008/10/peering-with-unknown-autonomous-system.html
>
>
> --
> Marko
> CCIE #18427 (SP)
> My network blog: http://cisco.markom.info/
>
> On Mon, Aug 10, 2009 at 07:31, Joe Astorino<jastorino_at_ipexpert.com> wrote:
> > I wanted to follow up on this with the group. B I think I misunderstood
> the
> > original question. So I think you are asking is there a way to know what
> the
> > incorrectly configured AS number is? B There is no way I know of.
> >
> > R2(config-router)#do sh run | s bgp
> > router bgp 2
> > B no synchronization
> > B bgp log-neighbor-changes
> > B neighbor 100.100.24.4 remote-as 99
> > B no auto-summary
> >
> > router bgp 4
> > B no synchronization
> > B bgp log-neighbor-changes
> > B neighbor 100.100.24.2 remote-as 2
> > B no auto-summary
> >
> > R2(config-router)#
> > *Jul 11 00:18:42.815: %BGP-3-NOTIFICATION: sent to neighbor 100.100.24.4
> 2/2
> > (peer in wrong AS) 2 bytes 0004 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF
> 002D
> > 0104 0004 00B4 6464 1804 1002 0601 0400 0100 0102 0280 0002 0202 00
> >
> > R4(config-router)#
> > *Aug 10 09:31:46.319: %BGP-3-NOTIFICATION: received from neighbor
> > 100.100.24.2 2/2 (peer in wrong AS) 2 bytes 0004
> >
> > On Mon, Aug 10, 2009 at 2:57 AM, Joe Astorino
> <jastorino_at_ipexpert.com>wrote:
> >
> >> It actually tells you exactly what you need there. B 0x0021 is the AS
> >> number. B Convert that to decimal and you are all set. So in this case,
> >> 0x0021 = AS 33
> >>
> >>
> >>
> >> On Mon, Aug 10, 2009 at 2:16 AM, Pradeep Malik
> <pradeepmlk_at_gmail.com>wrote:
> >>
> >>> Hi All,
> >>>
> >>> My question is; what debug cmds could we use to find out AS that
> neighbor
> >>> has configured for my peering B i.e B If I am X.X.X.X and this
> statement is
> >>> at B neighbor B " B bgp X.X.X.X remote-as Y" B B How to know AS Y ? B
> If I
> >>> troubleshoot on my router, it only gives below notification and it
> shows
> >>> hexa decimal value of AS configred at my side but not on neighbor
> side..
> >>>
> >>> *Dec B 9 14:25:00.010: %BGP-3-NOTIFICATION: received from neighbor
> >>> 150.2.3.254 2/2 (peer in wrong AS) 2 bytes 0021
> >>>
> >>> any suggestions ???
> >>>
> >>> Cheerz,
> >>> PM
> >>>
> >>>
> >>> Blogs and organic groups at http://www.ccie.net
> >>>
> >>>
> _______________________________________________________________________
> >>> Subscription information may be found at:
> >>> http://www.groupstudy.com/list/CCIELab.html
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >> --
> >> Regards,
> >>
> >> Joe Astorino - CCIE #24347 R&S
> >> Technical Instructor - IPexpert, Inc.
> >> Cell: +1.586.212.6107
> >> Fax: +1.810.454.0130
> >> Mailto: B jastorino_at_ipexpert.com
> >>
> >
> >
> >
> > --
> > Regards,
> >
> > Joe Astorino - CCIE #24347 R&S
> > Technical Instructor - IPexpert, Inc.
> > Cell: +1.586.212.6107
> > Fax: +1.810.454.0130
> > Mailto: B jastorino_at_ipexpert.com
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
>

-- 
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net