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 NLB and CLB.
Note In the following table, a hyphen (-) indicates that the feature is not supported and
a check mark (✓) indicates that the feature is supported.
| Feature type | Feature | Classic Load Balancer (CLB) | Network Load Balancer (NLB) |
|---|---|---|---|
| Listeners | TCP listeners | √ | √ |
| UDP listeners | √ | √ | |
| Listeners that use SSL over TCP | - | √ | |
| 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 | √ | √ | |
| Reliability | Cross-zone deployment | - | √ |
| Health checks | √ | √ | |
| Backend servers | Elastic Compute Service (ECS) instances, elastic network interfaces (ENIs), and elastic container instances | √ | √ |
| IP addresses | - | √ | |
| On-premises servers in a different region | - | √ | |
| Advanced features | Limits on new connections per second | - | √ |
| Listening by port range | - | √ | |
| Connection draining | - | √ | |
| Protocol versions | Dual-stack (IPv4 and IPv6) | - | √ |