250+ TOP MCQs on Packet Forwarding and Routing and Answers

Computer Networks online test on “Packet Forwarding and Routing”.

1. The term that is used to place packet in its route to its destination is called __________
a) Delayed
b) Urgent
c) Forwarding
d) Delivering

Answer: c
Clarification: Forwarding is done by the nodes in the path from source to destination, that are not the intended destination for the packet in order to pass the packet to the next node in the path. The destination machine does not forward the packet to any other node.

2. A second technique to reduce routing table and simplify searching process is called _________
a) Network-Specific Method
b) Network-Specific Motion
c) Network-Specific Maintaining
d) Network-Specific Membership

Answer: a
Clarification: In the network specific forwarding method, there is only one record, the destination of the packet, in the routing table and not the other hosts of the network. The other two forwarding methods are the default method and the next-hop method.

3. Next-Hop Method is used to reduce contents of a _________
a) Revolving table
b) Rotating Table
c) Routing Table
d) Re-allocate table

Answer: c
Clarification: In the next-hop forwarding method, the routing table of each router in the path contains the address of only the next hop in the path of packet. This method is suitable for short distances only.

4. Several techniques can make size of routing table manageable and also handle issues such as __________
a) Maturity
b) Error reporting
c) Tunneling
d) Security

Answer: d
Clarification: The size of the routing table in the technique must be manageable for the network nodes i.e. it must not be too big. Security of the forwarding packet is the highest priority for a technique and must be high enough so that only authorized senders and receivers can access the packet’s content.

5. Host-specific routing is used for purposes such as checking route or providing _____
a) Network Measures
b) Security Measures
c) Routing Measures
d) Delivery Measures

Answer: b
Clarification: In host-specific routing, the route of the packet is defined based on the exact match of the packet’s IP with the routing table entry of the host. It provides the best security for the packet as the packet is forwarded only to routers in the pre-defined path.

6. In Unicast routing, if instability is between three nodes, stability cannot be ________
a) Stable
b) Reversed
c) Guaranteed
d) Forward

Answer: c
Clarification: In Unicast routing, there is only sender and one receiver. So, if there is instability between three nodes, in which one is sender, one is receiver and one is the router in the path, there is no other path available for the packet and the stability of the network is not guaranteed.

7. In Unicast Routing, Dijkstra algorithm creates a shortest path tree from a ________
a) Graph
b) Tree
c) Network
d) Link

Answer: a
Clarification: The Djikstra’s shortest path algorithm is the fastest among the algorithms for finding the shortest path in a graph. But it is a greedy method based algorithm so it does not guarantee the shortest path every time.

8. In Multicast Routing Protocol, flooding is used to broadcast packets but it creates ________
a) Gaps
b) Loops
c) Holes
d) Links

Answer: b
Clarification: In multicast routing, there is one sender and many receivers. So flooding is the most basic method to forward packets to many receivers. The one issue with flooding is that it creates routing loops. One loop prevention method is that the routers will not send the packet to a node where the packet has been received before.

9. RPF stands for __________
a) Reverse Path Forwarding
b) Reverse Path Failure
c) Reverse Packet Forwarding
d) Reverse Protocol Failure

Answer: a
Clarification: Reverse Path Forwarding is a loop-free forwarding method for multi-cast routing in modern systems. The method on forwarding the packet away from the source IP in each iteration to make sure there is no loops.

10. LSP stands for __________
a) Link Stable Packet
b) Link State Packet
c) Link State Protocol
d) Link State Path

Answer: b
Clarification: A Link State Packet is a packet created by a router that lists its neighboring nodes and routers in link state routing protocol. It is shared with other routers to find the shortest path from a source to the destination.