[afnog] local pref issue with HE

[Patrick Okui]

On 26 Dec 2015, at 9:52, Mark Tinka wrote:

> On 25/Dec/15 17:40, Tarig Yassin wrote:
>> sorry for the mistake....
>>
>> I mean the 2nd link still preferred even it has longer AS-PATH.
>>
>> Also I've contacted *HE*, they said all routes received from AS_1299
>> "telia" will be assigned local_pref =70.
>> this is by design and can't be changed.
>>
>> this is a real issue for us, because we can't loadshare traffic
>> properly via AS-PREPEND technique.
>
> As others have already mentioned, LOCAL_PREF trumps AS_PATH prepends, 
> as a traffic engineering technique.
>
> Your options are to "intelligently" de-aggregate" (longest match 
> trumps everything else as a traffic engineering technique), or to 
> re-think how you choose your transit providers and how much bandwidth 
> you buy from each them.


Actually, since the prefix being announced is a /24 the way forward is 
to actually aggregate and withdraw the /24 on less desirable paths. Most 
people I’ve heard of will drop anything longer than a /24.

—
patrick