CCNA 2 V4 Chapter 8

The exhibit does not provide any specific information or details about the protocol used to distribute the routing information for the network 172.16.1.4. Therefore, an explanation for why the correct answer is RIPv2 cannot be provided.

With the "ip classless" command issued, router R2 will send the packet out Serial 0/0/1. This command allows the router to forward packets to a next-hop address even if the router does not have a specific route for the destination network. In this case, since there is no specific route for the host 172.16.4.234, the router will use the default route and send the packet out Serial 0/0/1.

A Cisco router uses administrative distance to select the preferred route to a destination network. Administrative distance is a measure of trustworthiness or reliability assigned to different routing protocols. When multiple routing protocols provide routes to the same destination network, the router compares their administrative distances. The route with the lowest administrative distance is considered the most reliable and is chosen to be installed in the routing table.

Router1 will apply a subnet mask of 255.255.255.0 to the child routes of the 172.16.0.0/24 network. This subnet mask allows for a maximum of 256 IP addresses, with the last octet being used for host addresses. Therefore, the child routes will have a network address of 172.16.0.0 and a subnet mask of 255.255.255.0.

When the router is issued the "ip classless" command, it means that the router is configured to forward packets to a specific interface if it has a more specific route to the destination IP address. In this case, since the destination IP address is 172.16.3.10, the router will forward the packets out of the interface Serial0/0/1.

The exhibit is not provided, so it is not possible to determine the exact routes mentioned in the question. Without the exhibit, it is not possible to generate an explanation for the given correct answer.

The router would use the RIP route to forward the packet. This is because the RIP route has the most specific matching network address (192.168.0.0/26) compared to the other routes. The router selects the route with the longest prefix match, so the RIP route with a subnet mask of /26 is more specific than the other routes with subnet masks of /24 and /25. Therefore, the router would choose the RIP route to forward the packet to the destination host with the address 192.168.0.58.

The first criterion used to determine the best path in the routing table is the route with the longest address and mask match to the destination. This means that the router will look for the route that has the most specific match to the destination IP address. By choosing the route with the longest address and mask match, the router ensures that the packet is forwarded to the most specific network, resulting in more efficient and accurate routing.

Router B will use the default route because it does not have a specific route for the destination address 10.16.1.97. The default route is used when there is no specific route available for a given destination.

The given network exhibits at least one parent and one child route.

After finding the static route in the routing table that matches the destination network for the packet, the router performs a recursive lookup to find the exit interface used to forward the packet. This means that the router will continue to search its routing table to determine the next hop for the packet until it finds a matching route with a specific exit interface. It will repeat this process until it reaches the final destination.

The parent network that will automatically be included in the routing table when the three subnets are configured on Router1 is 172.16.0.0/16. This is because it encompasses all the other subnets mentioned in the exhibit (172.16.0.0/24, 172.16.0.0/30, 172.16.1.0/16, and 172.16.1.0/24). The /16 subnet mask indicates that the first 16 bits of the IP address are fixed, allowing for a range of IP addresses that includes all the mentioned subnets.

This route is classified as a level 1 ultimate network route because it has a level 1 administrative distance and represents the ultimate network destination. The prefix 192.168.8.0/24 is being advertised through the next hop 192.168.4.1, which is reachable via the Serial0/0/1 interface. The [120/2] metric indicates that the route has an administrative distance of 120 and a metric value of 2.

The command "ip classless" should be issued by the administrator to ensure that packets destined for servers on the 172.16.254.0 network are sent out the gateway of last resort, Serial 0/0/1. This command enables the router to forward packets to a default route even if the router does not have a specific route for the destination network.

The correct answer is 172.16.0.0/25 because it is the first level 1 route in the routing table. In the routing table, routes are organized in a hierarchical manner based on their level. Level 1 routes are the most specific routes and have the longest prefix length. When a packet needs to be forwarded, the router will search for a matching route starting from the most specific routes (level 1) and moving towards less specific routes. Therefore, the router will first search for a match in the level 1 route 172.16.0.0/25.

When no ip classless is implemented on the router, it means that the router will not support classless IP addressing. This means that the router will assume it has knowledge of all subnets in the network and will not search beyond child routes for a better match. In other words, the router will not be able to dynamically determine the best route for a given destination based on the subnet mask. Instead, it will rely on the configured routes and assume it has complete knowledge of the network's subnets.

The output provided indicates that all of the routes listed in the routing table are network routes. This means that the router has specific routes for each network listed, rather than using a default route or a summarized route.

The correct answer is "do nothing, ip classless is on by default". This means that by default, the router will not drop packets for unknown child routes of the 172.16.0.0/24 network. The "ip classless" command enables the router to forward packets to a next-hop address even if the router does not have a specific route for the destination network. Therefore, there is no need for the network administrator to take any additional action in this scenario.

The command "ip classless" being enabled on the router determines if the router implements a classless route lookup process. This command allows the router to perform classless routing, which means it can forward packets to subnets that are not directly connected to it. Without this command enabled, the router would only be able to forward packets to directly connected networks, which is known as classful routing. Therefore, enabling the "ip classless" command allows the router to implement a classless route lookup process.