Speaker
Description
As server platforms increasingly ship with multiple frontend NICs, there is a growing need to utilize all available network paths transparently — without application changes. We propose a BPF-based approach that leverages cgroup hooks at connect() time to perform client-side path selection across multiple NICs, effectively implementing a form of TCP multipath at the host level. To avoid the operational complexity of distributing and synchronizing per-host NIC topology maps across an entire fleet, we further propose encoding the multi-NIC topology information directly in TCP Options during the connection handshake. This allows peers to dynamically discover available paths and perform load balancing decisions locally using BPF programs. We will present the design, discuss how it interacts with dynamic container networking environments, and share early deployment experience.