Layer 4 load balancing operates at the transport layer (OSI Layer 4), using TCP/UDP protocols to distribute traffic based on information like IP addresses and port numbers, without inspecting the application-layer content (Layer 7). Let’s evaluate each option:
A. Nginx:Nginx is a versatile web server and reverse proxy that supports both Layer 4 and Layer 7 load balancing. In its Layer 4 mode (e.g., with the stream module), it balances TCP/UDP traffic, making it a Layer 4 load balancing technology. This is widely used in Huawei’s CloudFabric DCN solutions for traffic distribution.TRUE.
B. PPP (Point-to-Point Protocol):PPP is a Layer 2 protocol used for establishing direct connections between two nodes, typically in WAN scenarios (e.g., dial-up or VPNs). It does not perform load balancing at Layer 4 or any layer, as it’s a point-to-point encapsulation protocol.FALSE.
C. LVS (Linux Virtual Server):LVS is a high-performance, open-source load balancing solution integrated into the Linux kernel. It operates at Layer 4, using techniques like NAT, IP tunneling, or direct routing to distribute TCP/UDP traffic across backend servers. It’s a core Layer 4 technology in enterprise DCNs.TRUE.
D. HAProxy:HAProxy is a high-availability load balancer that supports both Layer 4 (TCP mode) and Layer 7 (HTTP mode). In TCP mode, it balances traffic based on Layer 4 attributes, making it a Layer 4 load balancing technology. It’s commonly deployed in Huawei DCN environments.TRUE.
Thus,A (Nginx), C (LVS), and D (HAProxy)are Layer 4 load balancing technologies. PPP is not.References:Huawei CloudFabric Data Center Network Solution – Load Balancing Section; HCIP-Data Center Network Training – Network Traffic Management.
