I have a simple question. I'm using BGP with two different ISP's. ISPA and ISPB. Because of problems with ISPB, I have a filter in place that forces all traffic to ISPA even though I can still recive BGP updates from ISPB, and it's the one advertised on the internet. For example if I go to an internet router and traceroute to my site, and shows that it is going thru ISPB. But when I go out to the internet, it goes thru ISPA.
Here is the question: I know that when traffic originates from our site, by design (because of the filter.) it goes thru ISPA. But how is that traffic routed back to us? Does it uses the path that it originated from, or the path that's advertised on the internet.
Thanks for the help, and sorry for the long post.