24 Sep
2015
24 Sep
'15
9:47 a.m.
On 24/Sep/15 15:21, William Herrin wrote:
Hi Jason,
That's normal. Verizon does it too. Both have "community" tags which you can attach to your route advertisement. Each will have one that indicates they should give external routes the same "local pref" as the route you announce to them. Tagging your route announcement with the proper community will cause them to route based on AS path length as you expect.
Depending on the provider, this can't always be guaranteed, i.e., that the available LOCAL_PREF values a customer can trigger via a BGP community support anything <= what routes the network considers "external". What's possible (or available) may also be influenced by whether one's upstream is "transit-free" or not, I imagine. Mark.