Questions on Routing

Question 1

A router is required for communication between two PC’s with IP address 192.168.1.63/26 and 192.168.1.65/26 respectively.

A)True
B)False

Question 2

How many routing entries would be available on a routers routing table which has two interfaces configured with IP addresses 192.168.1.1/24 and 192.168.2.1/24 respectively?

A)None
B)1
C)2
D)3

Question 3

Which field in an incoming IP packet would be used by the router to perform a route lookup process?

A)Source IP address
B)Destination IP address
C)TTL
D)Subnet Mask

Question 4

A router has three directly connected networks – 192.168.1.0 /24, 192.168.2.0 /24, 192.168.3.0 /24. If a host 192.168.1.1 tries to access a host 192.168.2.1, does the router need to perform a route lookup for the destination when the IP packet from 192.168.1.1 reaches the router's interface?

A)Yes
B)No

Question 5

A PC does not have a default gateway configured on its TCP/IP adapter. Which of the following route entries would be unavailable in its routing table?

A)Default route
B)PC does not have routing table
C)Static route
D)Directly connected route

Question 6

The IP address of a PC is 192.168.1.2 /24 and the default gateway configured on the TCP/IP adapter setting on the PC is 192.168.1.1, which is the routers IP address for the network. If a user on the PC pings the website, www.tcpipguru.com, what would be the destination IP address of the IP packet carrying the icmp (ping) data send from the PC?

A)192.168.1.1
B)www.tcpipguru.com
C)The IP address of www.tcpipguru.com
D)The routers default gateways IP address

Question 7

A PC is configured with an IP address 192.168.1.2 and subnet mask 255.255.255.0. The default gateway on the TCP/IP adapter settings of the PC is not configured. The default gateway, which is the router, is configured with an IP address of 192.168.1.1 and subnet mask 255.255.255.0. What would happen if a user on the PC issues the command ping 192.168.1.1?

A)A response would be received from the router on the PC.
B)The packet would be dropped on the PC
C)The packet would be dropped on the router
D)The router would receive the packet, but a response would not be received by the PC.

Question 8

The IP address of a PC is 192.168.1.2/24 and the default gateway is 192.168.1.1. Which of the following actions would result in the request to be sent to the default gateway?

A)ping www.tcpipguru.com
B)http://www.tcpipguru.com (On the browser)
C)ping 192.168.2.3
D)All of the above

Question 9

How do routers derive network address for directly connected interfaces?

A)The network address has to be manually configured.
B)The network address is derived from the IP address and subnet mask configured on the interface
C)The network address is derived from the IP address configured on the interface.
D)A network address is not required for directly connected interfaces.

Question 10

Two routers are directly connected. What should be used so that the routing table on the routers is exchanged with each other?

A)This is not possible
B)Dynamic routing protocols should be configured on both the routers
C)The routing table information should be manually configured on both the routers
D)Routing tables would be exchanged since the routers are directly connected

Question 11

A PC is connected to a switch, which is connected to a router. The router is connected to the internet and has the default gateway configured on it. The PC does not have a default gateway configured on its TCP/IP adapter settings. Will the PC be able to access the internet?

A)Yes
B) No

Question 12

A router has three interfaces, E0, E1, and E2. If the router receives an Ethernet frame with destination mac-address FF-FF-FF-FF-FF-FF on E0, which among the following is true?

A)The router would forward the frame to E1 and E2 interface
B)The router will not forward the frame to E1 and E2 interface
C)The router would forward the frame on E0, E1 and E2 interface
D)None of the above

Question 13

What would a router do if it receives an IP packet with TTL value as 1?

A)The router would forward the packet to the appropriate destination.
B)The router would decrement the TTL value and then forward the packet
C)The router would drop the packet.
D)The next hop for the router would drop the packet.

When a router receives an IP packet with a Time-to-Live (TTL) value of 1, it means that the packet has already traversed one router or network segment, and the remaining TTL value indicates that the packet can only traverse one more hop before being discarded. In this scenario, the router performs the following actions:

1. **Decrement TTL Value:**

   - The router decrements the TTL value of the received packet by 1. This reduction represents the router's handling of the packet as it is considered one hop closer to its destination.

2. **Check TTL Value:**

   - After decrementing the TTL value, the router checks if the resulting TTL value is greater than zero. If the TTL value becomes zero or less, it indicates that the packet has reached the end of its permissible path and must be discarded.

3. **Forward or Discard Packet:**

   - If the TTL value is greater than zero after decrementing, the router forwards the packet toward its destination. The router will determine the next hop based on its routing table and forward the packet accordingly.

   - If the TTL value becomes zero or less after decrementing, the router discards the packet. This action prevents the packet from circulating endlessly in the network and ensures proper network operation.

4. **Generate ICMP Time Exceeded Message (Optional):**

   - In some cases, the router may generate an ICMP Time Exceeded message to inform the source host that the packet's TTL has expired. This message helps in network troubleshooting and diagnosing routing issues. However, the generation of ICMP messages in response to TTL expiration is optional and may be disabled depending on router configuration.

Overall, when a router receives an IP packet with a TTL value of 1, it decrements the TTL value, checks if the resulting value is greater than zero, and forwards the packet or discards it accordingly. This process ensures proper packet forwarding while preventing packets from circulating indefinitely in the network.

Question 14

A router has two directly connected networks – 192.168.1.0/24 and 192/168.2.0/24. What should be configured on the router for enabling communication between the networks?

A)Static routes
B)Any dynamic routing protocol
C)Since the networks are directly connected, additional configuration is not required.
D)None of the above

Question 15

Which of the following fields would be included in a class full routing protocol update packet?

A)Subnet Mask
B)Default Subnet Mask
C)Default gateway
D)None of the above

Question 16

A PC is connected to a switch, which is connected to a router. The management IP address of the switch is 192.168.1.3/24. The IP address of the PC is 192.168.1.2/24 and that of the router's interface is 192.168.1.1 /24. The default gateway of the router is 192.168.2.1 /24, which is used for internet access. What should be the default gateway on the PC, if it has to access the internet?

A)192.168.2.1
B)192.168.1.1
C)192.168.1.3
D)Default gateway is not required for internet access