Important Networking Q & A

1: What information must be stored in the route table?

** At a minimum, each entry of the routing table must include a destination address and the address of a next-hop router or an indication that the destination address is directly connected.

2: What does it mean when a route table says that an address is variably subnetted?

**Variably subnetted means that the router knows of more than one subnet mask for subnets of the same major IP address.

3: What are discontiguous subnets?

** Discontiguous subnets are two or more subnets of a major IP network address that are separated by a different major IP address.

4: What command is used to examine the route table in a Cisco router?

** show ip route is used to examine the routing table of a Cisco router.

5: What are the two bracketed numbers associated with the non-directly connected routes in the route table?

**The first bracketed number is the administrative distance of the routing protocol by which the route was learned. The second number is the metric of the route.

6: When static routes are configured to reference an exit interface instead of a next-hop address, in what way will the route table be different?

**When a static route is configured to reference an exit interface instead of a next-hop address, the destination address will be entered into the routing table as directly connected.

7: What is a summary route? In the context of static routing, how are summary routes useful?

**A summary route is a single route entry that points to multiple subnets or major IP addresses. In the context of static routes, summary routes can reduce the number of static routes that must be configured.

8: What is an administrative distance?

**An administrative distance is a rating of preference for a routing protocol or a static route. Every routing protocol and every static route has an administrative distance associated with it. When a router learns of a destination via more than one routing protocol or static route, it will use the route with the lowest administrative distance.

9: What is a floating static route?

** A floating static route is an alternative route to a destination. The administrative distance is set high enough that the floating static route is used only if a more-preferred route becomes unavailable.

10: What is the difference between equal-cost and unequal-cost load sharing?

**Equal-cost load sharing distributes traffic equally among multiple paths with equal metrics. Unequal-cost load sharing distributes packets among multiple paths with different metrics. The traffic will be distributed inversely proportional to the cost of the routes.