eBPF with XDP is the most suitable technology for deep packet inspection (DPI) on BlueField. It allows you to run custom code at near-line speed to inspect packets and apply security rules based on application signatures. TC and Netfilter are less efficient for DPI, OVS/OpenFlow are more for switching policies, and IPsec focuses on encryption.

The 'ngc config set' command uses '-apikey' to specify the API key directly. The correct syntax is 'ngc config set - to ensure the environment variable is properly expanded and passed as a string.

200GBASE-LR4 is the most appropriate. 'LR' designates Long Reach, typically up to 10km on single-mode fiber. SR4 is short reach (typically copper or very short fiber). ER4 is Extended Reach (up to 40km). CR4 is copper, for very short distances. DR4 is typically used for up to 500m to 2km distances depending on the specific implementation, so while possible LR4 is a better fit for guaranteed 2km.

The primary goal is to reduce latency and maximize bandwidth. Minimizing hops between frequently communicating GPUs is essential for achieving this. Server placement for cooling is a secondary concern, and topology choice should prioritize performance over simplicity. Subnet configuration and server placement relative to the network edge are less critical for NVLink-specific performance.

CM and CA are crucial for maintaining performance in InfiniBand fabrics. CM addresses congestion that has already occurred, while CA tries to prevent it. ECN is a key CA mechanism in InfiniBand. InfiniBand is lossless but experiences performance degradation if congestion occurs; CM helps mitigate this. They are not implemented at the IP layer; they are integral parts of the InfiniBand transport. Rate limiting is a viable CM strategy.