BGP Route Issues

Mon Aug 19 14:09:22 UTC 2013

yes of course..sorry for the typos


>________________________________
> From: Fakrul Alam Pappu <fakrulalam at gmail.com>
>To: Randy <randy_94108 at yahoo.com> 
>Cc: Blake Dunlap <ikiris at gmail.com>; Christopher Karel <chris.karel at gmail.com>; "nanog at nanog.org" <nanog at nanog.org> 
>Sent: Monday, August 19, 2013 5:27 AM
>Subject: Re: BGP Route Issues
> 
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>
>Won't it be backslash rather than forward slash? 
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>_([0-9]+) _\1_\1_\1_
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>On Mon, Aug 19, 2013 at 9:51 AM, Randy <randy_94108 at yahoo.com> wrote:
>
>11 prepends is beyond-excessive besides being annoying.
>>filter please _([0-9]+) _/1_/1_/1_
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>>>________________________________
>>> From: Blake Dunlap <ikiris at gmail.com>
>>>To: Christopher Karel <chris.karel at gmail.com>
>>>Cc: "nanog at nanog.org" <nanog at nanog.org>
>>>Sent: Sunday, August 18, 2013 7:42 PM
>>>Subject: Re: BGP Route Issues
>>
>>>
>>>
>>>Local Pref (which is common by the way to be set so customers > peers >
>>>transit). AS Path doesn't beat it.
>>>You can only request people follow the routes you want ingress, there's
>>>nothing you can do to force them to take a path to you short of
>>>deaggregation, and that only works until they notice it, and it irratates
>>>the rest of the world as well by using additional route slots.
>>>
>>>Poor routing is purely a viewpoint problem, not necessarily in agreement
>>>between all parties.
>>>
>>>-Blake
>>>
>>>
>>>On Sun, Aug 18, 2013 at 8:33 PM, Christopher Karel <chris.karel at gmail.com>wrote:
>>>
>>>>   Good evening,
>>>>
>>>>     I'm hoping you guys might be able to offer some advice or insight into
>>>> a BGP problem I've got.  I've noticed some strange routes between our
>>>> network, AS27270, and AS22943.  It looks like both our networks are dual
>>>> homed.  One ISP as the primary, and the other used as a backup, with path
>>>> prepending to prevent it from actually being used except in an outage.
>>>>  However, our route to 22943 appears to be using their backup link.  (27270
>>>> 4323 7018 22943 22943 22943 22943 22943 22943 22943 22943 22943 22943
>>>> 22943)  Which is strange, because we can reach their primary ISP without
>>>> any such rigmarole.
>>>>
>>>>     Playing around with Looking Glass servers indicates that Cogent
>>>> (AS174) has a similar backup route to our network.  (174 22402 27270 27270
>>>> 27270 27270 27270 27270)  Everywhere else I check seems perfectly sane.
>>>>  But since Cogent is essentially in-between the two networks I'm
>>>> troubleshooting, I would assume that the other network has a similar route.
>>>>  But Cogent won't talk with me about this, since I'm not a customer.
>>>>
>>>>     So as far as advice goes, is there a common issue that might result in
>>>> such poor routes in both directions?  Any further troubleshooting that I
>>>> should be doing?  Or any ideas on how to help remedy things that appear to
>>>> be outside our network/ISP?  Or are we doing something so wrong that this
>>>> is all my fault?
>>>>
>>>> I'd really appreciate any input on this.
>>>>
>>>>
>>>
>>>
>>>
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