Link Aggregation Control Protocol (LACP) is widely used in ISP and enterprise networks to combine multiple physical links into a single logical interface. In this complete guide, you will learn how to configure LACP between a MikroTik Router and a C-DATA OLT step by step. This setup helps achieve higher bandwidth, redundancy, and better network stability.
What is LACP and Why It Is Important?
LACP (IEEE 802.3ad) allows multiple Ethernet links to work together as one bonded interface. Instead of relying on a single uplink cable, ISPs use LACP to increase total throughput and ensure failover protection. If one cable fails, traffic automatically shifts to the remaining active links without service interruption.
In ISP environments, especially when connecting MikroTik routers with OLT devices like C-DATA, LACP ensures stable upstream connectivity and balanced traffic distribution across links.
Step 1: Check MikroTik RouterOS Compatibility
Before starting the configuration, ensure that your MikroTik router is running a RouterOS version that supports bonding and LACP. Both RouterOS v6 and v7 support 802.3ad bonding. It is recommended to update to the latest stable version to avoid bugs and compatibility issues.
Also verify that the Ethernet interfaces you plan to use are not already assigned to other bridges or configurations.
Step 2: Create LACP Bonding Interface on MikroTik
Now you need to create a bonding interface on the MikroTik router using LACP mode. This bonding interface will combine multiple Ethernet ports into one logical interface.
/interface bonding add name=LACP-C-DATA-OLT mode=802.3ad slaves=sfp-sfpplus2,sfp-sfpplus4 transmit-hash-policy=layer-2-and-3 disabled=no
The 802.3ad mode enables LACP, while the transmit-hash-policy ensures better traffic distribution. The lacp-rate=1sec option helps detect link failure faster.
Step 3: VLANs Creation on Mikrotik Router
Now we will create multiple VLANs on top of the bonding interface. Since my OLT has 4 physical ports, we will create a total of 5 VLANs:
- 1 VLAN will be used for OLT management
- The remaining 4 VLANs will be used to access and operate the PON ports.
This setup allows us to properly manage the OLT and distribute traffic through each PON port efficiently. We are creating VLANs ranging from 500 to 504. VLAN 500 is reserved for OLT management. We will assign a management IP on VLAN 500 to access and manage the OLT.The remaining VLANs will be used for the OLT PON ports.So, let’s get started.
/interface/bonding add interface=LACP-C-DATA-OLT name=C-DATA-EPON-1 vlan-id=201 add interface=LACP-C-DATA-OLT name=C-DATA-EPON-2 vlan-id=202 add interface=LACP-C-DATA-OLT name=C-DATA-EPON-3 vlan-id=203 add interface=LACP-C-DATA-OLT name=C-DATA-EPON-4 vlan-id=204 add interface=LACP-C-DATA-OLT name=C-DATA-MGMT vlan-id=200
Step 4: Configure LACP on C-DATA OLT
Next, log in to the C-DATA OLT via CLI and configure LACP on the corresponding uplink ports. The exact commands may vary slightly depending on the C-DATA model and firmware version, but the logic remains the same.
**************************************************************** ** EPON OLT Integrated Operating System. ** ** Device Model : FD1208S ** ** Hardware version : V3.0 ** ** Firmware version : V1.6.0_241021 ** ** BuildDate : Mon, 21 Oct 2024 18:43:08 +0800 ** ** Mac Address : E0:67:B3:7A:0D:F1 ** **************************************************************** >>User name:root >>User password: OLT> enable OLT# config OLT(config)# OLT(config)# interface link-aggregation OLT(config-interface-aggregation)# member add xge 0/0 1,2 link-aggregation group 10 OLT(config-interface-aggregation)# vlan mode 10 trunk OLT(config-interface-aggregation)# vlan trunk 10 200-204 OLT(config-interface-aggregation)# exit OLT(config)# save The percentage of saved data is: 0% The percentage of saved data is: 2% The percentage of saved data is: 5% The percentage of saved data is: 8% The percentage of saved data is: 11% The percentage of saved data is: 14% The percentage of saved data is: 17% The percentage of saved data is: 20% The percentage of saved data is: 23% The percentage of saved data is: 26% The percentage of saved data is: 29% The percentage of saved data is: 32% The percentage of saved data is: 35% The percentage of saved data is: 38% The percentage of saved data is: 41% The percentage of saved data is: 44% The percentage of saved data is: 47% The percentage of saved data is: 68% The percentage of saved data is: 81% The percentage of saved data is: 95% The percentage of saved data is: 100% OLT(config)#
Here, the mode active command enables LACP negotiation. Both MikroTik and C-DATA must use active LACP mode to properly establish the aggregated link.
Step 5: Verify LACP Status on MikroTik
Once both sides are configured, you should verify the LACP status on the MikroTik router. This confirms whether the links are successfully aggregated.
/interface bonding monitor LACP-C-DATA-OLT
If the configuration is correct, you will see all slave interfaces listed as active. If any port shows inactive status, double-check cabling and configuration on both ends.
Step 6: Verify LACP Status on C-DATA OLT
On the C-DATA OLT, use verification commands to confirm that the LACP group is up and running. This helps ensure that traffic is properly balanced across all member links.
OLT(config)# show link-aggregation group summary
You should see the channel group in an active state with all member ports bundled correctly.
Best Practices for ISP Networks
For ISP environments, always use high-quality cables and identical port speeds on both sides of the LACP link. Mixing different speeds can cause unstable behavior and performance issues.
Regularly monitor LACP status and traffic statistics to ensure links are functioning optimally. This proactive approach helps prevent downtime and customer complaints.
Conclusion
Configuring LACP between a MikroTik router and a C-DATA OLT is an essential step for building a high-availability and high-performance ISP network. By following this complete step-by-step guide, you can ensure reliable uplink connectivity, automatic failover, and efficient bandwidth utilization.
If you manage ISP or enterprise networks, mastering LACP configuration will significantly improve your network stability and scalability.