Module 8: Network Layer
Which layer is responsible for taking an IP packet and preparing it for transmission over the communications medium?
Data Link
Which default gateway statement is true?
The default gateway address is the IP address of the router on the local network.
A computer has to send a packet to a destination host in the same LAN. How will the packet be sent?
The packet will be sent directly to the destination host.
What is the command used on a Cisco IOS router to view the routing table?
show ip route
This type of route is also known as a gateway of last resort.
Default route
Which field in an IPv4 packet header will typically stay the same during its transmission?
Destination Address
Which information is used by routers to forward a data packet toward its destination?
Destination IP address
What is the term for splitting up an IP packet when forwarding it from one medium to another medium with a smaller MTU?
Fragmentation
Which field is used to detect corruption in the IPv4 header?
Header Checksum
Which field in an IPv6 packet is used by the router to determine if a packet has expired and should be dropped?
Hop Limit
What does the IPv6 header include.
It consists of 40 octets. It contains 8 header fields.
Which field includes common values such as ICMP (1), TCP (6), and UDP (17)?
Protocol
What information is added during encapsulation at OSI Layer 3?
Source and destination IP address
Which statement is correct about IPv4 packet header fields?
The source and destination IPv4 addresses remain the same while travelling from source to destination.
What improvements is provided by IPv6 as compared to IPv4?
Uses a simpler header to provide improved packet handling Increased the IP address space
Which IPv4 address can a host use to ping the loopback interface?
127.0.0.1
What does a code of "O" indicate next to a route in the routing table?
A route learned dynamically from OSPF
Which delivery method does not guarantee that the packet will be delivered fully without errors?
Best effort
What are major issues associated with IPv4?
IP address depletion Lack of end-to-end connectivity Increased network complexity and Internet routing table expansion
Which statement accurately describes a characteristic of IPv4?
IPv4 has a 32-bit address space.
Which statement about host forwarding decisions is true?
Local hosts can reach each other without the need of a router.
What are the two most commonly referenced fields in an IPv4 packet header that indicate where the packet is coming from and where it is going?
Source IP address Destination IP address
Which is true of the IPv6 packet header?
The Hop Limit field replaces the IPv4 Time to Live field.
Which characteristic describes an IPv6 enhancement over IPv4?
The IPv6 header is simpler than the IPv4 header is, which improves packet handling.
How does the network layer use the MTU value?
The MTU is passed to the network layer by the data link layer.
Which is a characteristic of static routes?
They are manually configured.
What was the reason for the creation and implementation of IPv6?
To relieve IPv4 address depletion
Which OSI layer sends segments to be encapsulated in an IPv4 or IPv6 packet?
Transport Layer
True or False? A router can be configured with a combination of both static routes and a dynamic routing protocol.
True
When a connectionless protocol is in use at a lower layer of the OSI model, how is missing data detected and retransmitted if necessary?
Upper-layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host.
Which command can be used on a Windows host to display the routing table?
netstat -r
Which two commands could be entered on a Windows host to view its IPv4 and IPv6 routing table?
netstat -r route print
When a router receives a packet, what information must be examined in order for the packet to be forwarded to a remote destination?
Destination IP address
