What is LACP?
LACP (Link Aggregation Control Protocol) is a protocol from the IEEE 802.3ad family that allows multiple physical Ethernet links to be combined into a single logical interface (link aggregation). This increases bandwidth and provides fault tolerance.
Key Functions
- Automatic creation and management of aggregated links
- Traffic distribution across member links
- Monitoring and disabling of failed links
LACP dynamically manages link bundles, ensuring high availability of network connections.
How It Works
Formation Steps:
- Initiating aggregation on devices
- Exchanging LACPDU (Link Aggregation Control Protocol Data Units)
- Negotiating and bundling links
- Forwarding traffic via the logical interface
Use Cases:
- Link aggregation between switches
- Connection between a server and a switch
- Linking two routers
Table: LACP Modes
| Mode | Description |
|---|---|
| Active | Actively initiates aggregation |
| Passive | Waits for and responds to initiation |
| On (Static) | No LACP; manually configured aggregation |
FAQ
Can you aggregate ports with different speeds?
No. All ports in the group must have the same speed and duplex settings.
Is LACP only for physical devices?
No. It is also supported by virtual switches (e.g., vSwitch, OVS).
Conclusion
LACP is an effective solution for load balancing and enhancing reliability in availability-critical networks. It is supported by both data centers and enterprise environments.
