CCNA 2 Routing and Switching Essentials v5 Chapter 6: Static Routing – Check Your Understanding Questions Answers
1. Which statement is true concerning configuring static routes using next-hop addresses?
- Routers cannot use more than one static route with a next-hop address.
- When the router identifies that a packet is destined for a route associated with a nexthop address in the routing table, the router requires no further information and can immediately forward the packet.
- Routers configured with the static route using a next-hop address must either have the exit interface listed in the route or have another route with the network of the next hop and an associated exit interface.
- Routes associated with a next-hop address are more efficient than routes going to exit interfaces.
Explanation: All routes in the routing table must be resolved to an exit interface in the routing table. If a route has only a next-hop IP address, that next-hop address must eventually be resolved to another route in the routing table that does include an exit interface, such as a directly connected network. Some static routes, such as those with Ethernet exit interfaces, can include both an exit interface and a next-hop IP address.
2. Which of the following are three characteristics of a static route? (Choose three.)
- Reduces the memory and processing burdens on a router
- Ensures that there is always a path available
- Used to dynamically find the best path to a destination network
- Used for routers that connect to stub networks
- Used for networks with a single route to a destination network
- Reduces configuration time
Explanation: Configuring a static route does not ensure that the path is always available. If the exit interface or next-hop IP address is in the up state, the static route will be included in the routing table, regardless of whether the destination network is available. Dynamic routing protocols are typically a better option when there are multiple routes to the same destination network. The routing protocol will be able to automatically determine the best path.
3. Which option shows a correctly configured IPv4 default static route?
- ip route 0.0.0.0 0.0.0.0 S0/0/0
- ip route 0.0.0.0 255.255.255.0 S0/0/0
- ip route 0.0.0.0 255.255.255.255 S0/0/0
- ip route 0.0.0.0 255.0.0.0 S0/0/0
Explanation: The static route ip route 0.0.0.0 0.0.0.0 S0/0/0 is considered a default static route and will match all destination networks.
4. A network administrator enters the following command into Router1: ip route 192.168.0.0 255.255.255.0 S0/1/0. Router1 then receives a packet that is destined for 192.168.0.22/24. After finding the recently configured static route in the routing table, what does Router1 do next to process the packet?
- Drops the packet because the destination host is not listed in the routing table
- Looks up the MAC address of the S0/1/0 interface to determine the destination MAC address of the new frame
- Performs a recursive lookup for the IP address of the S0/1/0 interface before forwarding the packet
- Encapsulates the packet into a frame for the WAN link and forwards the packet out the S0/1/0 interface
Explanation: The router will encapsulate the packet for the WAN link and then forward the packet out the S0/1/0 interface. The packet will not be dropped because the destination is in the routing table. The MAC address lookup will not be the next item to do to process the packet. A recursive lookup will not be required as the exit interface is identified in the route statement.
5. What type of static route is created when the next-hop IP address and exit interface are specified?
- Recursive static route
- Directly connected static route
- Fully specified static route
- Floating static route
Explanation: A fully specified static route has the next-hop IP address and exit interface specified. A recursive static route has only the next-hop IP address specified. A directly attached static route has only the router exit interface specified. A floating static route has a higher metric than the dynamic routes and serves as a backup route.
6. Why would a summarized static route be configured on a router?
- To reduce the number of public IP addresses required by an organization
- To provide a better route than a particular routing protocol
- To provide a default gateway for a router that connects to an ISP
- To reduce the size of the routing table
- To reduce the size of the routing protocol update to a neighboring router
Explanation: A summary route represents multiple networks. A summarized static route does not necessarily provide a better route than a routing protocol does. A default static route would provide a default gateway for a router that is connected to an ISP. Routing protocol updates may not necessarily be reduced in if static route routes are also used.
7. Which subnet mask would be used for a network that has a maximum of 300 devices?
- 255.255.255.0
- 255.255.254.0
- 255.255.252.0
- 255.255.248.0
- 255.255.240.0
Explanation: A subnet mask of 255.255.255.0 accommodates 254 devices (2A8 = 256 – 2 for the network number and broadcast). A subnet mask of 255.255.254.0 accommodates 510 devices. A subnet mask of 255.255.252.0 handles up to 1022 devices. A subnet mask of 255.255.248.0 supports up to 2046 devices. Finally, a mask of 255.255.240.0 is used for a network that needs up to 4094 addresses.
8. Which two conditions must exist in order to summarize IPv6 routes into a single static IPv6 route? (Choose two.)
- The destination networks are contiguous and can be summarized into a single network address.
- The multiple static routes all use different exit-interface or next-hop IPv6 address.
- The destination networks are not contiguous.
- The multiple static routes all use the same exit-interface or next-hop IPv6 address.
- The administrative distance is greater than the administrative distance of another static route or dynamic routes.
Explanation: Static IPv6 routes can be summarized into a single static IPv6 route if the destination networks are contiguous and can be summarized into a single network address. Moreover, all static routes have to use the same exit-interface or next-hop IPv6 address. Floating static routes are static routes that have an administrative distance greater than the administrative distance of another static or dynamic route.
9. What command, or set of commands, would be used to determine if the following configuration on router HQ works as designed?
ip route 0.0.0.0 0.0.0.0 serial 0/0/0 10 ip route 0.0.0.0 0.0.0.0 serial 0/1/0
- HQ# traceroute 128.107.0.99
- HQ# show ip route
- HQ(config)# interface serial 0/1/0
HQ(config-if)# shutdown
HQ(config-if)# end
HQ# show ip route - HQ# ping 128.107.0.99
HQ# ping 64.100.0.5 - HQ# show ip interface brief
Explanation: To test a floating static route, take down the main route/link in order to see whether the backup link appears in the routing table. The show ip route command simply shows the routing table. Only one of the static routes would be shown at any one time.
10. Which is avalid summary route for networks 192.168.8.0/22, 192.168.12.0/22, and 192.168.16.0/22?
- 192.168.0.0/18
- 192.168.0.0/19
- 192.168.0.0/20
- 192.168.8.0/21
Explanation: The third octet of the network addresses represented in binary are
8 = 00001000
12 = 00001100
16 = 00010000
The common leftmost bits are 000 in all three octets. Thus, the summary route will be 192.168.0.0/19.