Cisco CCNA mock exam questions sample test – Question 336

To minimize routing protocol traffic, you have decided to use static routing in the network displayed in the following diagram. You would like to keep the configuration as simple as
possible.

336
Which command(s) are required for all hosts to communicate with one another and the Internet? (Choose all that apply.)

A. R1(config)#ip route 12.168.5.0 255.255.255.0 192.168.5.1
B. R2(config)#ip route 0.0.0.0 255.255.255.0 192.168.5.2
C. R1(config-if)# ip route 12.168.5.0 255.255.255.0 192.168.5.1
D. R2(config-if)# ip route 0.0.0.0 255.255.255.0 192.168.5.2
E. R2(config)#ip route 12.168.5.0 255.255.255.0 192.168.5.1
F. R1(config)#ip route 0.0.0.0 0.0.0.0 192.168.5.2


Correct Answer: EF

Explanation:
There must be two routes added to make the network functional. From a conceptual standpoint, the network requires the following two routes:
A static default route on R1 that directs all traffic destined for unknown networks (which would include Internet-bound traffic) to R2
A static route on R2 to direct traffic destined for 12.168.5.0/24 to R1. Without this route R2 will be unable to route return traffic to the 12.168.5.0/245 network even if the default route in the first bullet point has been added.
The commands that would create these routes, respectively, are:
R2(config)#ip route 12.168.5.0 255.255.255.0 192.168.5.1
R1(config)#ip route 0.0.0.0 0.0.0.0 192.168.5.2
Troubleshooting routing problems should always begin with examining the routing table of the routers involved in the path to the destination. If the routes are static, they will also appear in the output of the show run command. One of the characteristics of a static route is that it will remain in the routing table even if routers on the path to the destination network lose their route to the network. If an advertising router loses its route to a destination network, dynamic routes will be removed from the routing tables of the routers that received that advertisement.
Static routes not only reduce routing update traffic in stub networks such as this one, but they also increase security because only the network administrator may change the routing table. On the other hand, the administrator must also stand ready to manually add new routes if current routes become unavailable. Dynamic routing is designed to make these route changes automatically if alternate routes exist.
The commands R1(config-if)# ip route 12.168.5.0 255.255.255.0 192.168.5.1 and R2(config-if)# ip route 0.0.0.0 255.255.255.0 192.168.5.2 are incorrect because they are executed at an interface prompt, rather than at the global configuration prompt as required.
The command ip route 12.168.5.0 255.255.255.0 192.168.5.1 is the correct command to create a static route to direct traffic destined for 12.168.5.0/24 to R1. However, this command should be executed on R2, not at the R1(config)# prompt.
The command ip route 0.0.0.0 0.0.0.0 192.168.5.2 is the correct command to create a static default route that directs all traffic destined for unknown networks (which would include Internet-bound traffic) to R2. However, this command should be executed on R1 and not at the R2(config)# prompt.

Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot IPv4 and IPv6 static routing
References:
Cisco IOS IP Configuration Guide, Release 12.2 > Configuring IP Routing Protocol-Independent Features > Configuring Static Routes