AT&T -> Qwest ... Localpref issue?

Graham Wooden graham at
Sun Aug 7 08:30:39 CDT 2011

Thanks Paul.

Localpref with Qwest on my AT&T prefixes was 100 until last week ... So my
prepends to balance between the two was working just fine for the past 2
years or so.
My announcements to CenturyLink to Qwest are coming out as 100.

I am not a direct customer of Qwest, so sending the community of 209:70
won¹t work (already tried that).  I am a direct customer of CenturyLink and
unfortunately the two networks haven¹t really come together as one just yet.
I sent a note to AT&T ­ maybe the can help do something, as I reviewed the
communities with them and I am already doing what I need to do.

The main problem here is that our CenturyLink connection is pure crap ...
Even originating routes from their network, I had them take our AT&T (the
other transit at this particular POP) - faster and less hops (go figure).
At our other pops with more than 1 transits, we like to utilize both as much
as possible.  

Contract is up in December ... can¹t wait until it¹s gone.

On 8/6/11 11:57 PM, "PC" <paul4004 at> wrote:

> Qwest uses 80 for peers; 100 for customers.  As I'm sure Qwest had AT&T as a
> peer prior to today (and you tagged as a customer), it probably should have
> been 80 since the beginning.  What was the local pref to AT&T before?  Maybe
> they found a misconfiguration on a router.
> If your only objective is to make your Qwest peering "backup", send community
> 209:70 to Qwest and it'll drop your local pref on their network to 70.  This
> will cause their 80 local pref peering with AT&T to be preferred.
> I also suggest you read:
> and
> However, depending on if your network topology and situational circumstances
> permit it, it may not be a bad idea to take on-net customer routes for
> performance reasons.
> On Sat, Aug 6, 2011 at 8:51 PM, Graham Wooden <graham at> wrote:
>> Hi folks,
>> Anyone else noticed a localpref change on Qwest network in regards to AT&T
>> prefixes?  I noticed my AT&T assigned prefixes dropping to 80, causing my
>> backup transit peering with Centurylink to take preference with Qwest
>> originators ...  All was working fine with my prepends .. But not anymore...
>> Any insight would be great. I haven¹t reached out to AT&T or Qwest yet.
>> Curious if this is a bigger change than just me.
>> Thanks,
>> -graham

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