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

Graham Wooden graham at
Sun Aug 7 13:53:05 UTC 2011

I should also note that Centurylink has been less than cooperative on even
thinking about changing my routes to a pref of 70 on our behalf (they don't
accept communities). I think time to get the account rep involved ...

On 8/7/11 8:30 AM, "Graham Wooden" <graham at> wrote:

> 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

More information about the NANOG mailing list