BGP Path Attribute Filtering, YES or NO?

Wed Jan 8 14:36:29 UTC 2020

On 8/Jan/20 16:26, James Jun wrote:

>
> I get that you'd want to reset MED on peering sessions, but any particular
> rationale on why you'd rewrite MED to 0 on customer sessions?
>
> I would argue that providing the ability for customers to transfer backhaul
> costs onto their transit provider is one of the compelling commercial reasons
>  *for* IP transit vs. other modes of IP interconnection. 
>
> Conversely speaking, I would also argue that transit provider *should* forward
> meaningful MED values on its route advertisements to customers.  If a customer
> wants to cold potato his outbound traffic on his own network, that's entirely
> his call; he has the option of rewriting MED to 0 if he wants closest exit
> to his transit instead.
>
> Most transit providers (at least in US, I can't imagine it's much different
> in EU) will permit downstream customers to cold potato traffic through their
> network. 

We provide customers with a ton of LOCAL_PREF options they can activate
in our network via communities:

    http://as37100.net/?bgp

As I mentioned to Saku re: the ORIGIN attribute, I don't mind customers
using this on us since we have sufficient backbone capacity in all
markets, and they pay us to provide them with a port in each market. So
if customers want to change our LOCAL_PREF values in order to push
traffic some way or another, we are okay with this, since it's $$.

Mark.