Tuesday, January 10, 2017

Networking questions part 1

I'm going to try to submit questions at least once a month this year (hopefully more often)

Here's the first batch, enjoy....

1. What layer of the OSI Reference Model sends and receives bits and specifies the electrical, mechanical, procedural and functional requirements for maintaining a physical link between end systems?

A) Session
B) Transport
C) Network
D) Data Link
E) Physical

2. What Cisco IOS keyboard shortcut recalls the oldest command in the command history, beginning with the most recent command?

A) Ctrl+B
B) Ctrl+E
C) Ctrl+U
D) Ctrl+N
E) Ctrl+P

3. What does Router(config)# no access-list 1 command achieve?

A) Removes Access List 1
B) Disables ACL on interface 1
C) Nothing, this is not a Cisco command

4. When would an interface need a clock rate?

A) When the interface is DTE
B) When the interface is DCE

5, What is Cisco's default NAT table entry timeout (translation timeout)?

A) 1 hour
B) 12 hours
C) 24 hours
D) 36 hours
E) 48 hours

6. What is the maximum number of subnets given the following?
(Assume ip subnet-zero is enabled)

A) 4
B) 8
C) 16
D) 32
E) 64

7. What is port 21 used for?

A) FTP data
B) FTP program
C) Telnet

8. What does the term "Logical address" refer to?
A) MAC address
B) Physical address
C) IP address
D) Link-layer address

9. What is the maximum number of hosts you can assign to a class C network if it is not subnetted?

A) 1024
B) 254
C) 32
D) 512
E) 65025

10. A router has two Fast Ethernet interfaces and needs to connect to four VLANs in the local network. How can you accomplish this task, using the fewest physical interfaces and without decreasing network performance?

A. Use a hub to connect the four VLANS with a Fast Ethernet interface on the router.
B. Add a second router to handle the VLAN traffic.
C. Add two more Fast Ethernet interfaces.
D. Implement a router-on-a-stick configuration.

1. Correct Answer E


2. Correct Answer E

Keyboard Shortcut Action

Up Arrow Displays your previous commands.  (command history)
TAB Key Completes a partially typed CLI commands.
CTRL+Z Takes you back to Privileged EXEC Mode.

CTRL+A Places the cursor at the beginning of a line.
CTRL+E Places the cursor at the end of a line.
CTRL+R Redisplays the current command line.
CTRL+W Erases a word (behind the cursor).
CTRL+U Erases an entire line.

3. Correct Answer A

If you wish to remove an access-list, you use the no access-list (list #) command.

4. Correct Answer B

Cisco routers are DTEs by default (Data Terminal Equipment). The DCE (Data Circuit-Terminating Equipment) at the other end of the connection must supply a clock rate to the DTE.

5. Correct Answer C

When an entry is placed into the NAT table a timer begins, the duration of this timer is called the translation timeout, defaulted to 24 hours on Cisco routers.

6. Correct Answer A is a class C address.  The subnet mask implies 2 bits are borrowed.
22 = 4 subnets

7. Correct Answer B

File Transfer Protocol (FTP) is a network protocol used to copy files from one host to another over a TCP/IP-based network.
A client makes a TCP connection to the server's port 21. This connection remains open for the duration of the session called the control connection, with a second connection, called the data connection, opened by the server from its port 20 to a client port required to transfer file data.

8. Correct Answer C

A Logical address is normally a 32-bit IP address assigned to each host in an IPv4 network.

A Physical address is a unique 48-bit flat address normally burned into the ROM of the NIC card, and therefore cannot be changed. It is divided into 24-bit vendor code and 24-bit serial address.

9. Correct Answer B

For class C the number of bits for host address portion is 8. So 2^8 -2 = 256-2 = 254 hosts.

10. Correct Answer D

A router on a stick allows you to use sub-interfaces to create multiple logical networks on a
single physical interface.

How did you go? If you disagree with any of my answers or find errors, please leave a comment. More coming soon..stay tuned :-)

I remind myself every morning: Nothing I say this day will teach me anything. So if I'm going to learn, I must do it by listening.
Larry King