Which administrative distance (AD) is defined for EIGRP external routes?

The administrative distance (AD) for EIGRP external routes is defined as 170. This value is significant because it indicates the trustworthiness of the EIGRP external routes compared to other routing protocols. In the context of routing, the administrative distance serves as a metric for routers to determine which routing protocol to prefer when multiple routes to the same destination exist.

EIGRP internal routes, for example, have an AD of 90, making them more preferred than external routes, which reflects the hierarchy of trust among routing protocols. The higher AD of external routes at 170 suggests that they are less preferred compared to internal routes and many other routing protocols. This can be especially important in situations where both internal and external EIGRP routes are present, as it helps to maintain network stability and reliability by ensuring the best routes are chosen for data transmission.

In summary, the value of 170 for EIGRP external routes is crucial in routing protocol selection and highlights the importance of understanding administrative distances when managing routing decisions in networking.