Configuring load balancing with MikroTik for three ISPs, where two ISPs use Equal-Cost Multi-Path (ECMP) and the third ISP employs static routing, involves a combination of routing policies and firewall rules. Below is a general guide to help you set up this scenario. Note that specific details may vary based on your network architecture and MikroTik RouterOS version.
1. Configure IP Addresses:
- Assign IP addresses to the relevant interfaces for each ISP.
/interface ethernet
add name=ether1-wan1
add name=ether2-wan2
add name=ether3-wan3/ip address
add interface=ether1-wan1 address=10.1.2.2/30
add interface=ether2-wan2 address=10.2.3.2/30
add interface=ether3-wan3 address=10.3.4.2/30
2. Configure ECMP for ISP1 and ISP2:
- Set up ECMP for ISP1 and ISP2.
/ip route
add dst-address=0.0.0.0/0 gateway=10.1.2.1 scope=10
add dst-address=0.0.0.0/0 gateway=10.2.3.1 scope=10
3. Configure Static Route for ISP3:
- Add a static route for ISP3.
/ip route
add dst-address=0.0.0.0/0 gateway=10.3.4.1 scope=10
4. Set Up ECMP for Client 172.2.2.0/24:
- Create an address list for the client network.
/ip firewall address-list
add list=client-network address=172.2.2.0/24
- Set up ECMP for the client network.
/ip route
add dst-address=172.2.2.0/24 gateway=10.1.2.1
add dst-address=172.2.2.0/24 gateway=10.2.3.1
5. Set Up Static Routing for Client 172.3.3.0/24:
- Add a static route for the static routing client network.
/ip route
add dst-address=172.3.3.0/24 gateway=10.3.4.1
6. Configure Firewall Mangle Rules:
- Create mangle rules to mark connections for each ISP.
/ip firewall mangle
add action=mark-routing chain=prerouting src-address-list=client-network new-routing-mark=to-isp1
add action=mark-routing chain=prerouting src-address-list=client-network new-routing-mark=to-isp2
add action=mark-routing chain=prerouting src-address=172.3.3.0/24 new-routing-mark=to-isp3
7. Configure NAT Rules:
- Set up NAT rules to masquerade traffic going out through each ISP.
/ip firewall nat
add action=masquerade chain=srcnat out-interface=ether1-wan1 routing-mark=to-isp1
add action=masquerade chain=srcnat out-interface=ether2-wan2 routing-mark=to-isp2
add action=masquerade chain=srcnat out-interface=ether3-wan3 routing-mark=to-isp3
8. Firewall Filter Rules:
- Create filter rules to accept established and related connections.
/ip firewall filter
add action=accept chain=input connection-state=established,related
add action=accept chain=output connection-state=established,related
These steps provide a basic configuration for load balancing with MikroTik using ECMP for two ISPs and static routing for the third ISP. Ensure that you adapt the configuration to your specific network setup, considering factors such as interface names, IP addresses, and subnet masks. Testing and monitoring the network behavior after applying these configurations are crucial to ensure proper load balancing and failover functionality.