I have 3 upstream providers. When I make prepend on one of providers, both upload and download change significantly.
I thought that with prepend I only influence incoming traffic (download) and with the local preference outgoing traffic (upload). On MRTG I see that both in & out traffic is getting down on provider that I made prepend, and on the other two both in & out is getting up. Does anyone know what is the explenation for this?