In MikroTik RouterOS, the difference between iBGP (Internal Border Gateway Protocol) and eBGP (External Border Gateway Protocol) is mainly defined by the “remote-as” parameter in the BGP configuration.

We explain how to determine if iBGP or eBGP is being used:

1. Local AS Number vs. Remote AS Number:
   • iBGP: Used when the AS (Autonomous System) number of the BGP neighbor (remote-as) is the same as the AS number of the local router. That is, both devices are within the same autonomous system.
   • eBGP: Used when the AS number of the BGP neighbor is different from the AS number of the local router, indicating that the devices are in different autonomous systems.
2. Configuration in RouterOS:
   • To configure or verify whether iBGP or eBGP is being used, you will need to access the BGP section in RouterOS settings. This can be done through the command line interface or through the graphical interface (WinBox).
   • Within the BGP configuration, look for the configuration of the BGP peers or neighbors. There you will find the “remote-as” parameter. If the number in “remote-as” is equal to the AS of the MikroTik router, then it is an iBGP configuration. If it is different, it is an eBGP configuration.
3. Example command:
   • You can check or configure this using commands like the following in the MikroTik terminal:
     
     /routing bgp peer print
     
     Learn to differentiate and configure iBGP and eBGP in MikroTik RouterOS, identifying the parameter remote-as.This command will show you the list of BGP neighbors and their respective configurations, including the remote AS.

By understanding these parameters and where to configure them, you can efficiently manage BGP relationships on your network using MikroTik RouterOS.