How to manipulate path in BGP so that Spoke site always connects to DC1 as primary & DC2 as backup.
Where DC1 & DC2 are both connected to different ISPs.
There are many ways to manipulate the best BGP path for any destination. Taking a look at the following lesson shows you the various attributes that you can modify to achieve the routing you want.
What you will actually use in your implementation depends upon whether you want to influence incoming or outgoing traffic, and will also depend upon whether or not the spoke and DCs are in the same AS or not.
Generally speaking, in your particular case, for outgoing traffic from the spoke site, the simplest method would probably be to use the weight attribute. Now if the spoke is in a different AS, and each DC is in a different AS, you may want to use local preference. But without knowing more about your topology, and the ultimate goal of your routing, we can’t make any more specific suggestions…
I hope this has been helpful!