Hello,
In a dual WAN setup with a Mikrotik router and PLDT modem where you are unable to disable the DHCP server on the PLDT modem, there can be potential issues if both devices are trying to assign IP addresses to the same network. Here are some scenarios and considerations to keep in mind:
1. IP Address Conflict: If both the PLDT modem and the Mikrotik router are running DHCP servers and assigning IP addresses in the same subnet range, there is a possibility of IP address conflicts. Devices on your network may receive conflicting IP addresses, leading to connectivity issues.
2. Double NAT: Having two DHCP servers on the same network can lead to a double NAT (Network Address Translation) situation, where both devices are performing NAT functions independently. This can complicate network configuration and may cause issues with certain applications or services that require port forwarding or specific network settings.
3. Subnet Isolation: If the PLDT modem and Mikrotik router are assigning IP addresses in different subnets, devices connected to each network may not be able to communicate with each other. This can lead to segmentation of your network and prevent devices from accessing resources across both networks.
4. Routing Issues: If the PLDT modem and Mikrotik router are each acting as DHCP servers and routing traffic independently, there may be routing conflicts or suboptimal routing paths within your network. This can impact network performance and cause connectivity issues.
To mitigate these potential problems, you may consider the following options:
1. Configure the Mikrotik router to act as the primary DHCP server for your network and disable DHCP on the PLDT modem if possible. This will help ensure that all devices on your network receive IP addresses from a single DHCP server.
2. If disabling DHCP on the PLDT modem is not an option, ensure that the DHCP ranges configured on both devices do not overlap. Assign a unique range of IP addresses to each device to avoid conflicts.
3. Consider placing the PLDT modem in bridge mode if supported. This will effectively disable the DHCP server on the modem and allow the Mikrotik router to handle all routing and DHCP functions.
4. If bridging the PLDT modem is not possible, you may need to carefully configure the IP settings on both devices to ensure they work together without causing conflicts or network segmentation.
It's important to test your network configuration thoroughly after making any changes to ensure that all devices can connect and communicate properly. If you continue to experience issues, you may need to reach out to your ISP for assistance or consider alternative network configurations.
I hope this information helps. If you have any further questions or need clarification, feel free to ask.
PH