Final answer:
The criteria listed refer to the prioritization of routes in a network by network devices like routers, which follow a specific order based on the most specific route, administrative distance of the protocol, metric of dynamic routes, priority of static routes, and the potential for equal cost multi-path routing.
Step-by-step explanation:
The list provided in the question is related to the criteria for prioritizing routes in a network, specifically within the context of routing decisions made by network devices such as routers. When a router has to decide between multiple routes to the same destination, the route selection process typically occurs in this order:
- Most specific route (longest netmask) - The route with the most specific matching subnet (i.e., the longest subnet mask or the highest number of bits in the mask) is preferred as it is considered the best match for the destination IP address.
- Lowest distance (protocol) - Administrative distance refers to the trustworthiness of the source of the route. Different routing protocols are assigned a default administrative distance value and a route from a protocol with a lower distance is preferred.
- Lowest metric (dynamic routes) - When routes are learned via the same protocol, the metric is used to determine the best path. The route with the lowest metric, which might represent the cost, hop count or other aspects, is chosen by the routing algorithm.
- Lowest priority (statics) - For static routes, the priority level can be set manually. The static route with the lowest priority number is preferred over higher numbered priorities.
- ECMP (Equal Cost Multi Path) - If multiple routes have the same cost or metric, load balancing between them may occur, allowing the router to distribute traffic across several equally preferable routes.