[165106] in North American Network Operators' Group
Re: BGP Route Issues
daemon@ATHENA.MIT.EDU (Randy)
Mon Aug 19 10:09:55 2013
Date: Mon, 19 Aug 2013 07:09:22 -0700 (PDT)
From: Randy <randy_94108@yahoo.com>
To: Fakrul Alam Pappu <fakrulalam@gmail.com>
In-Reply-To: <CAARHE5E4kwffSh_kVoCN-0K1zZuRYRS=F3oCo-OWkG+Zg7_z1w@mail.gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Reply-To: Randy <randy_94108@yahoo.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
yes of course..sorry for the typos=0A=0A=0A=0A=0A>_________________________=
_______=0A> From: Fakrul Alam Pappu <fakrulalam@gmail.com>=0A>To: Randy <ra=
ndy_94108@yahoo.com> =0A>Cc: Blake Dunlap <ikiris@gmail.com>; Christopher K=
arel <chris.karel@gmail.com>; "nanog@nanog.org" <nanog@nanog.org> =0A>Sent:=
Monday, August 19, 2013 5:27 AM=0A>Subject: Re: BGP Route Issues=0A> =0A>=
=0A>=0A>Won't it be backslash rather than forward slash? =0A>=0A>_([0-9]+) =
_\1_\1_\1_=0A>=0A>=0A>=0A>On Mon, Aug 19, 2013 at 9:51 AM, Randy <randy_941=
08@yahoo.com> wrote:=0A>=0A>11 prepends is beyond-excessive besides being a=
nnoying.=0A>>filter please _([0-9]+) _/1_/1_/1_=0A>>=0A>>=0A>>=0A>>=0A>>>__=
______________________________=0A>>> From: Blake Dunlap <ikiris@gmail.com>=
=0A>>>To: Christopher Karel <chris.karel@gmail.com>=0A>>>Cc: "nanog@nanog.o=
rg" <nanog@nanog.org>=0A>>>Sent: Sunday, August 18, 2013 7:42 PM=0A>>>Subje=
ct: Re: BGP Route Issues=0A>>=0A>>>=0A>>>=0A>>>Local Pref (which is common =
by the way to be set so customers > peers >=0A>>>transit). AS Path doesn't =
beat it.=0A>>>You can only request people follow the routes you want ingres=
s, there's=0A>>>nothing you can do to force them to take a path to you shor=
t of=0A>>>deaggregation, and that only works until they notice it, and it i=
rratates=0A>>>the rest of the world as well by using additional route slots=
.=0A>>>=0A>>>Poor routing is purely a viewpoint problem, not necessarily in=
agreement=0A>>>between all parties.=0A>>>=0A>>>-Blake=0A>>>=0A>>>=0A>>>On =
Sun, Aug 18, 2013 at 8:33 PM, Christopher Karel <chris.karel@gmail.com>wrot=
e:=0A>>>=0A>>>>=A0 =A0Good evening,=0A>>>>=0A>>>>=A0 =A0 =A0I'm hoping you =
guys might be able to offer some advice or insight into=0A>>>> a BGP proble=
m I've got.=A0 I've noticed some strange routes between our=0A>>>> network,=
AS27270, and AS22943.=A0 It looks like both our networks are dual=0A>>>> h=
omed.=A0 One ISP as the primary, and the other used as a backup, with path=
=0A>>>> prepending to prevent it from actually being used except in an outa=
ge.=0A>>>>=A0 However, our route to 22943 appears to be using their backup =
link.=A0 (27270=0A>>>> 4323 7018 22943 22943 22943 22943 22943 22943 22943 =
22943 22943 22943=0A>>>> 22943)=A0 Which is strange, because we can reach t=
heir primary ISP without=0A>>>> any such rigmarole.=0A>>>>=0A>>>>=A0 =A0 =
=A0Playing around with Looking Glass servers indicates that Cogent=0A>>>> (=
AS174) has a similar backup route to our network.=A0 (174 22402 27270 27270=
=0A>>>> 27270 27270 27270 27270)=A0 Everywhere else I check seems perfectly=
sane.=0A>>>>=A0 But since Cogent is essentially in-between the two network=
s I'm=0A>>>> troubleshooting, I would assume that the other network has a s=
imilar route.=0A>>>>=A0 But Cogent won't talk with me about this, since I'm=
not a customer.=0A>>>>=0A>>>>=A0 =A0 =A0So as far as advice goes, is there=
a common issue that might result in=0A>>>> such poor routes in both direct=
ions?=A0 Any further troubleshooting that I=0A>>>> should be doing?=A0 Or a=
ny ideas on how to help remedy things that appear to=0A>>>> be outside our =
network/ISP?=A0 Or are we doing something so wrong that this=0A>>>> is all =
my fault?=0A>>>>=0A>>>> I'd really appreciate any input on this.=0A>>>>=0A>=
>>>=0A>>>=0A>>>=0A>>>=0A>>=0A>=0A>=0A>
