Domain 9: Networking Fundamentals

Which of the following IP addresses have a default subnet mask of 255.255.0.0? (select three)

191.168.2.15 168.16.5.1 129.0.0.1

You want yo implement a protocol on your network that allows computers to find the IP address of a host from a logical name. Which protocol should you implement?

DNS

Which of the following configuration files holds the name of the host?

/etc/HOSTNAME

Which of the following files contain information that enables a Linux system to resolve IP addresses to FQDN/host names. (choose all that apply)

/etc/hosts /etc/resolv.conf

Which file should you edit to determine the order in which name resolution is done?

/etc/nsswitch.conf

What is the default subnet mask for address 132.44.156.67?

255.255.0.0

You are configuring the IP address for a host and have been asked to use the address 192.160.99.110/16 . What subnet mask value would you use?

255.255.0.0

What is the default subnet mask for the IP address 203.111.3.3?

255.255.255.0

Which file in the Linux system lists all network services, including the port assigned to the service?

/etc/services

Which of the following are DHCP client components?

dhcpcd pump

You are troubleshooting a workstation that is having trouble while browsing the internet. You want to perform some tests on name resolution. Which utility would give you the most information?

dig

Which command displays the IP address and subnet mask values configured on a workstation?

ifconfig

You are troubleshooting a connectivity problem on a Linux server. You are able to connect to another system on the local network, but are not able to connect to a server on a remote network. You suspect that the default gateway information for the system may be configured incorrectly. Which of the following commands would you use to view the default gateway information on the Linux server?

ifconfig

Which network service would you use to get the IP address from the FQDN hostname?

DNS

Which utility would you use to view current connections and active sessions and ports on a computer?

netstat

You would like to see how many different computers are currently connected to your local workstation. Which of the following commands would allow you to do this?

netstat

Which of the following utilities would you use to view the routing table?

route

You have replaced the default gateway on your network. The gateway had used the Ip address of 201.12.3.4 and you must remove it from the routing table. Which command would you use to accomplish this?

route del default gw 201.12.3.4

You are having trouble contacting a host on another network. Ping fails, but you would like to get more information about the router in the path where the communication stops. Which of the following utilities would you use?

traceroute

Which of the following protocols allows hosts to exchange messages to indicate problems with packet delivery?

ICMP

Which of the following protocols includes extensive error checking to ensure that a transmission is sent and received without mistakes?

TCP

You are an application developer and are writing a program to exchange video files through a TCP/IP network. You need to select a transport protocol that will guarantee delivery. Which TCP/IP protocol would you implement that provides this capability?

TCP

Which of the following network protocols must be used to connect to the internet?

TCP/IP

Which of the following is a valid IPv6 address?

FEC0::AB:9007

Which of the following commands would not bring the first Ethernet interface down?

/etc/sysconfig/network-scripts/ifcfg-eth0 down

You are configuring a network firewall to allow SMTP outbound e-mail traffic, and POP3 inbound e-mail traffic. Which of the following TCP/IP ports should you open on the firewall? (Select two)

110 25

Which of the following IP addresses belong to the Class A network 114.0.0.0? (select three)

114.0.0.15 114.58.12.0 114.122.66.12

You check the IP address on the network. The address is 122.16.155.71 with a mask of 255.0.0.0 . What is the broadcast address?

122.255.255.255

Which of the following describes an Ipv6 address? (select two)

128-bit address Eight hexadecimal quartets

Which of the following are valid IPv6 addresses? Select all that apply.

141:0:0:0:15:0:0:1 6384:1319:7700:7631:446A:5511:8940:2552

Which of the following IP addresses is a valid IP address for a host on a public network?

142.15.6.1

Which port numbers is used by the IMAP protocol?

143

Which of the following are not valid IP address? (select three)

145.8.260.7 257.0.122.55 45.22.156.256

Which port number is used by SNMP?

161

You have a computer that is connected to the Internet through a NAT router. You want to use a private addressing scheme for your computer. Which of the following IP addresses could you assign to the computer? (select all that apply)

172.18.188.67 192.168.12.253 10.0.12.15

You have a computer that is connected to the Internet through a NAT router. You want to use a private addressing scheme for your computer. Which of the following IP addresses could you assign to the computer? (select three)

172.18.188.67 192.168.12.253 10.0.12.15

Which of the following IP addresses are Class B addresses? (select three)

190.65.2.0 132.12.0.0 129.0.0.0

You are the administrator for a small network of Linux hosts. Your network does not communicate with the Internet and does not use DNS. When you add a new host named ENERGY7 to the network, which entry should be added to the /etc/hosts files?

192.168.0.34 ENERGY7 #Reception Area

What is the network address for the address 199.78.240.240 if the default subnet mask is used?

199.78.240.0

You have been told to assign the IP address 21.155.67.188 to a host on the network using the default subnet mask. Which mask should you use?

255.0.0.0

To transfer files to your company's internal network from home, you use FTP. The administrator has recently implemented a firewall at the network perimeter and disabled as many ports as possible. Now you can no longer make the FTP connection. You suspect the firewall is causing the issue. Which ports need to remain open so you can still transfer the files? (select two)

20 21

With a growing concern for security, you convince your boss to stop allowing telnet access to the network. Remote connections will now be allowed only through the use of ssh. Which port must you allow through the firewall for ssh access?

22

Which port does Telnet use?

23

Which of the following correctly describe the most common format for expressing IPv6 addresses? (select two)

32 numbers, grouped using colons Hexadecimal numbers

You want to maintain tight security on your internal network so you restrict access to the network through certain port numbers. If you want to allow users to continue to use DNS, which port should you enable?

53

You have just finished setting up an Apache Web server that will provide Web services to your company intranet. As part of the intranet solution, you need to be able to provide name resolution for clients on your company network. Which service should you install?

BIND

Which service can you use on your network to automatically assign IP addresses to hosts and to prevent the same address from being assigned two different hosts?

DHCP

You have a TCP/IP network with 50 hosts. There have been inconsistent communication problems between hosts. You run a protocol analyzer and discover that two hosts have the same IP address assigned.

DHCP

Which TCP/IP configuration parameter identifies the router that is used to reach hosts on remote networks?

Default Gateway

You are the system administrator of a test lab of computers running Linux. For security reasons your lab is not connected to the corporate network and therefore you are not able to resolve host names via the corporate DNS server. You do, however, want to be able to connect to the lab computers using host names, but you do not have the resources to bring up your own DNS server.

Enter Ip addresses and host names for all of the lab computers in the /etc/hosts file on each of the machines in the lab.

You ISP has changed the IP addresses of their DNS servers. What would you need to do on your Linux system to still be able to continue resolving host and fully qualified domain names if you use statically assigned IP address information?

Enter the IP addresses of the new DNS servers into the /etc/resolv.conf file.

You are attempting to ping the FQDN on a computer on the internet, but are not getting a response. What is the problem?

Pinging the FQDN on a computer does not give you enough information to know what the problem is.

Your computer has and IP address of 161.13.5.15 . Your computer is on a:

Public network

You are attempting to ping another computer on the Internet by its IP address, but you are not getting a response. You do however get a response when pinging a host your own network. Which of the following commands would help you better determine where the problem is?

Run traceroute on the IP address of the computer on the internet.

Which of the following network services or protocols uses TCP/IP port 22?

SSH

You open the /etc/nsswitch.conf file and observe the following line: hosts: files dns What is the result of this configuration?

The /etc/hosts file takes precedence over information obtained from a DNS server when resolving domain names.

You are asked to troubleshoot a problem on a user's computer. When the user types the name of any Web site, he gets a message "The page cannot be displayed". You determined that nothing has changed on the computer. What is the likely problem?

The DNS server is down or not rechable.

What would be the result of the following command? host.www.somedom.com

The IP address and A record name of the computer www.somedom.com would be displayed.

You attempt to telnet to system 192.168.1.240 . You get a message "Connecting To 192.168.1.240...Could not open connection to the host, on port 23. No connection could be made because the target machine actively refused it." What may be the problem?

The telnet server is not running.

Which of the following are good reasons to enable NAT?

To translate between Internet IP addresses and the IP addresses on your private network.

After arriving at work in the morning you turn on your Linux workstation and attempt to visit and Internet new site. After a few minutes your Web browser times out telling you that the Web site is unavailable. Which of the following troubleshooting steps would be helpful in determining the problem? (choose all that apply)

Use ping command to ping the FQDN and IP addresses of the web site you are trying to reach. Use the traceroute command to traceroute the FQDN and IP address of the Web site you are trying to reach.

You have just finished configuring a new network card in your Linux system. You would like to verify that it is configured to access the internet. Which of the following solutions would best help you verify that you have internet access?

attempt to ping a site on the internet.

Which command should you use to find the IP address for the xyzcomp.com

host xyzcomp.com

A user calls the help desk to report that she is unable to connect to the network after an upgrade of the Linux operating system. You suspect the problem is related to the network configuration. Which command would you use to quickly see the current IP address(es) asigned to her computer?

ifconfig -a

Which command would you use to configure the IP address of 192.168.0.123 for the first Ethernet card in a host?

ifconfig eth0 192.168.0.1213

You need to temporarily change the IP address of your first Ethernet interface (eth0) to 192.168.1.50 where it is currently set to 10.0.1.50 . Which of the following commands would achieve the desired result?

ifconfig eth0 192.168.1.50

You need to set the IP address for eth1 for 192.168.15.2 with a subnet mask of 255.255.255.0 . Which command is correct?

ifconfig eth1 192.168.15.2 netmask 255.255.255.0

As you troubleshoot the network connection for you Linux system, you discover the eth1 interface is down. Which command should you use to start the interface?

ifup eth1

The Eth1 interface is currently down. Which command will start the Eth1 interface?

ifup eth1

Which command displays network activity statistics for TCP, UDP, and IP?

netstat -s

Which of the following commands verifies that TCP/IP is working correctly on the local computer?

ping 127.0.0.1

Which of the following commands can be used to retrieve the IP address and/or FQDN/host name information from a DNS server? (choose all that apply)

nslookup host dig

Which of the following commands would allow you to see if a remote computer is reachable?

ping

Which of the following commands could you use to view your local system's default gateway? (choose all that apply)

route netstat -r

After an acquisition of another company, you are in a position where you must add another network to the existing routing tables. Which of the following commands would you use to accomplish this?

route add -net 11.12.13.14/24 gw 201.12.3.4

As a system administrator you need to add a static route so that you can reach host 195.156.76.122 255.255.255.0 . Which command will work?

route add -net 195.156.76.0 netmask 255.255.255.0 dev eth0

As a system administrator you are going to add a static for host 195.157.66.221, 255.255.255.0 . Your default gateway is 192.168.5.1 but you want this route to use gateway 192.168.7.1 . Which command will work?

route add -net 195.157.66.0 netmask 255.255.255.0 gw 192.168.7.1

As a system administrator you want to block (reject) any packets from 170.122.0.0.255.255.0.0 . Which command will block those packets?

route add 170.122.0.0 nermask 255.255.0.0 reject

While working on a Linux server, you are unable to connect to Windows Server 2003 system across the Internet. You are able to ping the default gateway on your own network, so you suspect that the problem lies outside of the local network. Which utility would you use to track the route a packet takes as it crosses the network?

traceroute

Which utility is similar to traceroute but does not require elevated privileges?

tracepath

Which command could you use to see the path that packet traveled across a network to a remote host?

traceroute

Which troubleshooting a problem on a Linux system, you run a utility that generates the following output: Which of the following utilities were you using?

traceroute