Network Layer

Which of the following assertions is FALSE about the Internet Protocol (IP) ?

• It is possible for a computer to have multiple IP addresses

• IP packets from the same source to the same destination can take different routes in the network

• IP ensures that a packet is discarded if it is unable to reach its destination within a given number of hops

• The packet source cannot set the route of an outgoing packets; the route is determined only by the routing tables in the routers on the way

Which of the following functionalities must be implemented by a transport protocol over and above the network protocol ?

• Recovery from packet losses

• Detection of duplicate packets

• Packet delivery in the correct order

• End to end connectivity

The subnet mask for a particular network is 255.255.31.0. Which of the following pairs of IP addresses could belong to this network?

• 172.57.88.62 and 172.56.87.233

• 10.35.28.2 and 10.35.29.4

• 191.203.31.87 and 191.234.31.88

• 128.8.129.43 and 128.8.161.55

Which of the following is NOT true with respect to a transparent bridge and a router?

• Both bridge and router selectively forward data packets

• A bridge uses IP addresses while a router uses MAC addresses

• A bridge builds up its routing table by inspect­ing incoming packets

• A router can connect between a LAN and a WAN

Packets of the same session may be routed through different paths in:

• TCP, but not UDP

• TCP and UDP

• UDP, but not TCP

• Neither TCP nor UDP

The address resolution protocol (ARP) is used for:

• Finding the IP address from the DNS

• Finding the IP address of the default gateway

• Finding the IP address that corresponds to a MAC address

• Finding the MAC address that corresponds to an IP address

An organization has a class B network and wishes to form subnets for 64 departments. The subnet mask would be:

• 255.255.0.0

• 255.255.64.0

• 255.255.128.0

• 255.255.252.0

For which one of the following reasons does Internet Protocol (IP) use the timeto- live (TTL) field in the IP datagram header

• Ensure packets reach destination within that time

• Discard packets that reach later than that time

• Prevent packets from looping indefinitely

• Limit the time for which a packet gets queued in intermediate routers.

Two computers C1 and C2 are configured as follows. C1 has IP address 203.197.2.53 and netmask 255.255.128.0. C2 has IP address 203.197.75.201 and netmask 255.255.192.0. which one of the following statements is true?

• C1 and C2 both assume they are on the same network

• C2 assumes C1 is on same network, but C1 assumes C2 is on a different network

• C1 assumes C2 is on same network, but C2 assumes C1 is on a different network

• C1 and C2 both assume they are on different networks.

The address of a class B host is to be split into subnets with a 6-bit subnet number. What is the maximum number of subnets and the maximum number of hosts in each subnet?

• 62 subnets and 262142 hosts.

• 64 subnets and 262142 hosts.

• 62 subnets and 1022 hosts.

• 64 subnets and 1024 hosts.