This topic describes the features of Network Load Balancer (NLB). This topic also describes the differences between the Layer 4 capabilities of NLB and Classic Load Balancer (CLB).
The following table describes the features of NLB and the differences between the features of NLB and CLB.
In the following table, a hyphen (-) indicates that the feature is not supported and a check mark (✔) indicates that the feature is supported.
Category | Feature | CLB | NLB |
Listeners | TCP listeners | ✔ | ✔ |
UDP listeners | ✔ | ✔ | |
TCP/SSL listeners | - | ✔ | |
Scheduling algorithms | Round-robin | ✔ | ✔ |
Weighted round-robin | ✔ | ✔ | |
Consistent hashing based on source IP addresses | ✔ | ✔ | |
Consistent hashing based on four elements | ✔ | ✔ | |
Consistent hashing based on QUIC IDs | ✔ | ✔ | |
Weighted least connections | - | ✔ | |
Reliability | Multiple active zones | - | ✔ |
Health checks | ✔ | ✔ | |
Backend servers | Elastic Compute Service (ECS) instances, elastic network interfaces (ENIs), and elastic container instances | ✔ | ✔ |
IP addresses | - | ✔ | |
Servers across zones and on-premises servers | - | ✔ | |
Advanced features | Limits on new connections | - | ✔ |
Listening by port range (Anyport) | - | ✔ | |
Connection draining | - | ✔ | |
IP versions | Dual-stack (IPv4 and IPv6) | - | ✔ |