Does a router prefer a lower or higher Administrative Distance (AD) when selecting routes?

When a router selects routes, it prefers a lower Administrative Distance (AD). Administrative Distance is a value that routers use to determine the reliability of a particular routing source; the lower the AD, the more trustworthy that source is considered.

For instance, a route learned through a static route will have a lower AD than a route learned via a dynamic routing protocol such as RIP or OSPF. This means that if a router receives two routing updates for the same destination from different sources, it will select the route with the lower AD as the preferred route to ensure that it is using the most reliable and preferred path.

Understanding the concept of Administrative Distance is crucial for network design and troubleshooting, as it directly affects routing decisions and network performance.