I have a infrastructure with 5 servers and one Arista switch.
The Arista switch have a iBGP with 2 upstreams, and receive the routes/traffic from them.
The Arista have also a connection with 5 servers, every server with 2x 10G in LACP/Port-Channel mode.
In every server, we have multiple GRE tunnels with customers on another Country. We delivery our "regional" traffic to the customers through the GRE tunnels.
However, some customers have large DDoS attacks, and it should be "balanced" through all servers through ECMP.
Our objective is to set-up a ECMP across all servers to mitigate the dirty traffic, and delivery them for the GRE tunnels without change all our infrastructure.