Routing Fundamentals Flashcards
The laptops used by a sales team are unable to connect to the devices used by the marketing team. Both the devices belong to different VLANs within a network. Which statements are true with regard to troubleshooting the connectivity issue between the two VLANs? (Choose all that apply.)
A. Ensure that the DNS values are correctly updated on the users’ laptops.
B. Ensure that the correct default gateway is configured on the laptops the sales team uses.
C. Ensure that the router has the route to the destination VLAN.
D. Check for a local LAN connectivity issue.
B. Ensure that the correct default gateway is configured on the laptops the sales team uses.
C. Ensure that the router has the route to the destination VLAN.
D. Check for a local LAN connectivity issue.
The following statements are true with regard to troubleshooting the connectivity issue between two VLANs:
1 Ensure that the correct default gateway is configured on the laptops the sales team uses.
2) Check for a local LAN connectivity issue.
3) Ensure that the router has the route to the destination VLAN.The default gateway should be reachable as it acts as an exit point for the VLAN. Use the ip route command to check if the route is available for the destination address. Use the ping and traceroute command to check the LAN connectivity.
A network administrator needs to forward packets based on IP addresses. The packet to the network 192.172.16.0/24 should be forwarded to the IP address 192.169.16.2, whereas the packet with the IP address 192.172.16.10 should be forwarded to 192.179.16.2. What command needs to be configured to configure the host route and the network route? (Choose all that apply.)
A. ip route 192.172.16.0 255.255.255.0 192.169.16.2
B. ip route 192.172.16.10 255.255.255.0 192.179.16.2
C. ip route 192.172.16.10 255.255.255.255 192.179.16.2
D. ip route 192.172.16.0 192.179.16.2 fa0/0
A. ip route 192.172.16.0 255.255.255.0 192.169.16.2
C. ip route 192.172.16.10 255.255.255.255 192.179.16.2
The “ip route 192.172.16.10 255.255.255.255 192.179.16.2” command is used to configure the host route, and the “ip route 192.172.16.0 255.255.255.0 192.169.16.2” command is used to configure the network route. The two routes overlap, but the router uses the most specific route to send packets. The host route is defined as a route for a single host address with the subnet mask /32. A network route defines the route to an IP network or subnet.
The network 172.168.10.2 255.255.255.0 has been advertised using RIP and IGRP using default admin distance. The show ip route command output displays only the route using the RIP protocol. Why is the IGRP route not displayed in the routing table? (Choose all that apply)
A. A better competing RIP route is available with a higher administrative distance.
B. The outgoing interface listed in the ip route for IGRP is down.
C. A route that matches the next hop address is unavailable.
D. The metric value for IGRP is higher than RIP.
B. The outgoing interface listed in the ip route for IGRP is down.
C. A route that matches the next hop address is unavailable.
The IGRP route is not displayed in the routing table due to the following reasons:
1) The outgoing interface listed in the ip route for IGRP is down.
2) A route that matches the next hop address is unavailable.
The administrative distance for RIP is 120, whereas that for IGRP is 120. The ip route will lower the administrative distance updated in the routing table if there are more than two routes for the same network. If the outgoing interface or next hop is down, the routing table will update the next available route on the network.
Host A needs to send a packet each to host B and C. Hosts A and B are located in the headquarters, whereas Host C is at a remote site. Which statements are true with respect to IP routing? (Choose all that apply.)
A. Host A sends the packet to the default gateway.
B. Host A sends the packet directly to Host B.
C. Host A sends the packet directly to Host C.
D.The packet sent to Host C is discarded.
A. Host A sends the packet to the default gateway.
B. Host A sends the packet directly to Host B.
The following statements are true with respect to IP routing:
- Host A sends the packet directly to Host B.
- Host A sends the packet to the default gateway.
If the destination is local, a device can send a data packet directly. But, if the destination is remote, the device sends a data packet to the default gateway.
The network administrator needs data communication between five VLANs configured on a hub site switch. For example, the Sales VLAN device should be able to communicate with the Marketing VLAN devices and so on. How should the router be configured so that the least router interface is used for VLAN communication? (Choose all that apply.)
A. Ensure a unique sub-interface is created for each VLAN that needs to be routed.
B. Use the encapsulation dot1q vlan_id command.
C. Define the ip address ip-address mask command to configure IP settings.
D. Each router interface should be assigned one VLAN.
A. Ensure a unique sub-interface is created for each VLAN that needs to be routed.
B. Use the encapsulation dot1q vlan_id command.
C. Define the ip address ip-address mask command to configure IP settings.
The router should be configured in the following ways to use the least router interface for VLAN communication:
1) Ensure that a unique sub-interface is created for each VLAN that needs to be routed.
2) Use the encapsulation dot1q vlan_id command.
3) Define the ip address ip-address mask command to configure IP settings.
By default, devices in the same VLAN are able to communicate. To enable communication between different VLANs, an administrator needs to use either a layer-three switch or a router. One of the best ways to achieve this is to divide a router interface into logical interfaces for each VLAN. Set the interface to trunk with the encapsulation command.
A remote site has a backup link configured in case the primary link fails. The existing route used to forward packets is an IGP route. The routing table of the router is as follows:
R1#show ip route
Gateway of last resort is not set
192.116.10.0/24 is subnetted, 1 subnets
C 192.116.1.0 is directly connected, Ethernet0
I 10.10.0.0/8 [100/1200] via 192.116.1.200, 00:00:03, Ethernet0
C 172.168.1.0/24 is directly connected, Loopback0
What command needs to be used to activate the backup link if the primary link fails?
A. ip route 192.116.1.0 255.255.255.0 interface Ethernet0
B. ip route 10.10.0.0 [90/1100] via 192.116.1.200 Serial0/0
C. ip route 10.10.0.0 255.0.0.0 Dialer 1 250
D. ip route 172.168.1.0/24 is directly connected, Loopback0
C. ip route 10.10.0.0 255.0.0.0 Dialer 1 250
To activate the backup link in case the primary link fails, use the “ip route 10.10.0.0 255.0.0.0 Dialer 1 250” command.
The network administrator needs to configure a static route with an administrative distance greater than the route of the primary link. The routing table shows only the best route for each network. If a secondary route exists, it will be updated only when the primary route is unreachable. The static route configured is called the floating static route.
A network administrator needs to configure manual summarization for Routing Information Protocol version 2. What configuration changes are required on Cisco IOS router for manual summarization? (Choose all that apply.)
A. Auto summarization needs to be disabled on the Cisco IOS router.
B. The validation of source IP addresses should be disabled.
C. The IP address and network mask that identify the routes to be summarized need to be configured.
D. The authentication mode should be configured in the global configuration mode.
A. Auto summarization needs to be disabled on the Cisco IOS router.
C. The IP address and network mask that identify the routes to be summarized need to be configured.
The following configuration changes are required on the Cisco IOS router for manual summarization:
1) Auto summarization needs to be disabled on the Cisco IOS router.
2) The IP address and network mask that identify the routes to be summarized need to be configured.
The scalability and efficiency of a large network are improved by using summarizing routes in RIP version 2. The RIP database with summarized routes is processed first. The network administrator needs to use the “no auto-summary” command to disable auto-summarization on the Cisco IOS router. The former needs to use the “ip summary-address rip ip-address subnet mask” command on the interface where the summary address belongs.
What is the correct syntax to add a static route to a routing table?
A. ip route [destination_network] [mask] [next-hop_address or exit interface] [source_network]
B. ip route [destination_network] [mask] [next-hop_address or exit interface] [administrative_distance] [permanent]
C. ip route [destination_network] [next-hop_address or exit interface]
D. ip route [destination_network] [mask] [next-hop_address or exit interface] [administrative_distance] [source_network]
B. ip route [destination_network] [mask] [next-hop_address or exit interface] [administrative_distance] [permanent]
The following syntax is used to add a static route to a routing table:
ip route [destination_network] [mask] [next-hop_address or exit interface] [administrative_distance] [permanent]
The “ip route” command is used to create the static route.
The destination network is the network placed in the routing table.
Mask refers to the subnet mask used on the network.
The next-hop address is the IP address of the next-hop router that will receive packets and forward them to the remote network.
An exit interface is used in place of the next-hop address and is shown as a directly connected route.
Static routes have an administrative distance of 1 or 0 if an exit interface is used instead of a next-hop address.
If the interface is shut down or the router is unable to communicate with the next-hop router, the route will be automatically discarded from the routing table. Choosing the permanent option keeps the entry in the routing table, regardless of the consequence.
A network engineer has configured a new Cisco router with default route as the gateway of the last resort. The show ip route command displays the gateway of the last resort as not set. To troubleshoot the issue, the network engineer verifies the running configuration, which is given as follows:
Router#show running-config --Output discard-- ip routing ip route 172.168.10.4 255.255.255.0172.16.170.2 ip default- gateway 172.168.10.4 ip route 0.0.0.0 0.0.0.0 172.16.170.2
Why is the gateway of the last resort not set on the Cisco IOS router?
A. Static route already exists for the define network in the routing table.
B. The no auto summary command is missing on the router.
C. IP routing should be disabled on the router.
D. The ip default- network command should be configured in place of the ip default-gateway.
D. The ip default- network command should be configured in place of the ip default-gateway.
The ip default- network command should be configured in place of ip default-gateway to set the gateway of the last resort on a Cisco IOS router.
The ip default-network and ip route 0.0.0.0 0.0.0.0 commands are used to set the gateway of the last resort on Cisco routers. The IP routing should be enabled on a Cisco router. The gateway of the last resort is used to forward an IP packet to a destination for which the route is not found in the routing table.
On which algorithm does the routing protocol work? (Choose all that apply)
A. Link state
B. Distance metric
C. Distance vector
D. Speed of convergence
A. Link state
C. Distance vector
The algorithm used by a routing protocol is distance vector or link state.
The information the router knows about each route is defined by distance vector. The router learns the following information related to each route: the destination subnet, the routing protocol metric (distance), and the link/next hop used by the router for its route to the destination address (vector).
In the case of link state routing protocols, each router sends information about its link status to the entire network, due to which all routers understand the entire network topology.
A router runs an algorithm every time a network change is announced to identify the best routes throughout the network.
The routing protocol configured on a Cisco IOS router is the RIP protocol. It is observed that the router interface sends periodic updates even though no RIP router exists on the LAN interface. What are the reasons for disabling such routing updates from unnecessary interfaces? (Choose all that apply)
A. The receiving device will discard the RIPv1 updates processed by all LAN devices.
B. Advertising updates on the broadcasting network can pose security risk.
C. The unnecessary updates consume bandwidth, which is wastage of bandwidth.
D. It might create a broadcast storm within the network.
A. The receiving device will discard the RIPv1 updates processed by all LAN devices.
B. Advertising updates on the broadcasting network can pose security risk.
C. The unnecessary updates consume bandwidth, which is wastage of bandwidth.
Here are the reasons for disabling routing updates from unnecessary interfaces:
1) The unnecessary updates consume bandwidth, which is wastage of bandwidth.
2) Advertising updates on the broadcasting network can pose security risks.
3) The receiving device will discard the RIPv1 updates processed by all LAN devices.
To stop RIP updates from being propagated from any specific interface, an administrator needs to use the following commands:
router rip
passive-interface FastEthernet port number
What are the correct options with regard to administrative distance? (Choose all that apply.)
A. Administrative distance is used to measure the distance between the source and the destination address.
B. Administrative distance can’t be modified; all routing protocols are assigned with default administrative distance.
C. Administrative distance being 255 means no traffic will be passed using this route.
D. Administrative distance being zero is the most trusted route.
C. Administrative distance being 255 means no traffic will be passed using this route.
D. Administrative distance being zero is the most trusted route.
The correct options with regard to administrative distance are as follows:
1) Administrative distance being zero is the most trusted route.
2) Administrative distance being 255 means no traffic will be passed using this route.
The trustworthiness of routing information is defined by Administrative Distance (AD). The routing protocols are assigned a default administrative distance, but it can be modified at the CLI level.
An administrator doesn’t want to advertise an RIP network across all LAN and WAN interfaces on a Cisco router. What command does the administrator need to use to stop propagation of RIP updates from any specific interface?
A. router rip
passive-interface FastEthernet 0/1
B. router rip
interface FastEthernet 0/1 passive-rip
C. router rip
network 172.10.0.0 passive-interface FastEthernet 0/1
D. router rip
interface FastEthernet 0/1
passive network 172.10.0.0
A. router rip
passive-interface FastEthernet 0/1
To stop propagation of RIP updates from any specific interface, an administrator needs to use the following command:
router rip
passive-interface FastEthernet 0/1
It’s not necessary to advertise an RIP network over all WAN and LAN interfaces. So, the administrator can stop unwanted RIP updates using the passive-interface command. The command prevents RIP update broadcasts from being sent to the interfaces, but allows the interfaces to receive RIP updates.
A headquarter router receives an IP packet with the destination address as 10.20.1.15 and the source address as 10.20.10.15. What action will the router take, considering the following output?
HQrouter#show ip route
Codes: L - local, C - connected, S - static,
L 10.0.0.1/32 is directly connected, FastEthernet0/3
S 10.20.1.1/32 [120/2] via 10.10.10.2, 00:00:23, Serial0/0
S 10.20.20.0 [120/1] via 10.10.10.2, 00:00:23, Serial0/0
L 10.20.1.0/26 is directly connected, FastEthernet0/1
C 10.20.10.0 is directly connected, FastEthernet0/0
A. The packet will be routed out of FastEthernet0/1.
B. The packet will be discarded.
C. The router will broadcast considering the destination.
D. The packet will be routed out of FastEthernet0/0.
A. The packet will be routed out of FastEthernet0/1.
Considering the output of the headquarter router, the packet will be routed out of FastEthernet0/1. The routing table has a path to route packets to the 10.20.1.0 network. Hence, the headquarter router will route the IP packet to the destination address through the FastEthernet0/1 interface. The router will check if any routing path is available for the destination address. If not, the router will discard the packet by sending an ICMP destination unreachable message to the source LAN the packet originated from.
What is the default administrative distance for static routes and connected routes? (Choose all that apply.)
A. 1
B. 0
C. 110
D. 90
A. 1
B. 0
One and zero are the default administrative distance for static routes and connected routes, respectively.
An administrator can change the default value by adding an administrative weight at the end of a command.
