Yes, in the BGP configuration on a MikroTik device, you can use the loopback address as the router-id. In fact, this is a common and recommended practice in many BGP setups for several reasons:

Advantages of Using Loopback Address as Router-ID

1. Stability: The router-id is a unique identifier used in BGP processes to identify a router within the network. Using the loopback address ensures that the router-id don't change even if the main interface goes down. Loopback addresses are virtual interfaces and do not depend on the state of physical interfaces, making them stable and always available.
2. Ease of Management: Use the loopback address as router-id Simplifies network management as loopback addresses are easy to remember and manage compared to other IP addresses that could be assigned dynamically or change over time.
3. Better Connectivity in Complex Networks: In larger or more complex networks, the use of the loopback address helps ensure that the router-id It is accessible from different parts of the network, facilitating communication between BGP routers through multiple paths.

How to Configure the Router-ID in MikroTik

To configure the router-id on a BGP instance on MikroTik RouterOS, you can follow the following steps (assuming you already have a loopback address configured):

1. Access your MikroTik Router: You can do it through WinBox or through the command line (SSH or local terminal).
2. Navigate to BGP Settings:
   • In the CLI, you would enter the following commands:
     
     /routing bgp instance
set [nombre_de_tu_instancia] router-id=[tu_dirección_loopback]
     
   • Make sure to replace [nombre_de_tu_instancia] y [tu_dirección_loopback] with the name of your BGP instance and the loopback address configured on your device, respectively.
3. Check Settings:
   • To make sure the router-id has been set successfully, you can verify the configuration with the following command:
     
     /routing bgp instance print
     
   • This will display the configuration of all BGP instances, including the router-id configured.

Using the loopback address as router-id in BGP configurations is a good practice that improves network reliability and management, and is widely used in production environments.