What is the administrative distance (AD) for iBGP?

The administrative distance (AD) for iBGP (Internal Border Gateway Protocol) is set at 200. Administrative distance is a value used by routers to determine the trustworthiness of different routing protocols. Lower values indicate more trusted routes.

In the case of iBGP, which is used for routing between routers within the same autonomous system, the AD of 200 is significant because it ensures that iBGP routes are not preferred over other routing protocols that might have lower AD values, such as OSPF (with an AD of 110) or EIGRP (with an AD of 90). This separation is important because iBGP can potentially advertise routes that may not be optimal or loop-free within an autonomous system, so it is designed to have a higher AD to allow for dynamic routing adjustments based on the network's topology and the preferences of different routing protocols.

This understanding of iBGP's administrative distance is crucial for network design and troubleshooting, as it helps in effectively managing routing decisions and ensuring better network performance.