COMP1298-01 Networks and Applications, Ch 13

What zone configuration file contains a PTR record used to identify the loopback adapter?

/var/named/named.local

Where is the default document root directory for the Apache web server?

/var/www/html​

What kind of servers resolve fully qualified domain names to IP addresses for a certain namespace on the Internet?

DNS

Select the SQL statement below that can be used to delete a database:

DROP DATABASE

What directive below in Apache's httpd.conf file specifies that the index.html file in the document root directory will be sent to clients who request an HTML document?

DirectoryIndex index.html

What port is used by the Network Time Protocol (NTP) for communication?

UDP 123

Describe the DNS lookup process.

When you contact a Web server on the Internet using a Web browser, the Web browser performs a forward lookup of the FQDN such that it can contact the IP address of the Web server. This forward lookup can be performed by a DNS server or a series of DNS servers. ​ For example, if a Linux client is resolving www.linux.org, the Linux computer sends a forward lookup request for www.linux.org to the DNS server that is configured in NIC properties or /etc/resolv.conf; this is typically the DNS server at your ISP. If the ISP DNS server has recently resolved the FQDN and placed the result in its local DNS cache, you receive the response immediately (a DNS lookup query that generates a reply from a DNS cache is called an iterative query). If it has not, the ISP DNS server normally contacts the DNS server for the .org top-level zone and repeats the forward lookup request for www.linux.org (called a recursive query). The .org DNS server will not contain the IP address for the www.linux.org computer in its zone but will reply with the IP address of the DNS server for the linux.org zone. ​ Your ISP DNS server then contacts the DNS server for the linux.org zone and repeats the forward lookup request for www.linux.org (another recursive query). The DNS server for the linux.org domain contains a record that lists the IP address for the www.linux.org computer and returns this IP address to the ISP DNS server. The ISP DNS server then returns the result to the client Web browser, which then uses the IP address to connect to the Web server.

What command can be used to view and modify the date and time within the BIOS?​

hwclock

What ftp command uploads the filename from the current directory on the local computer to the current directory on the remote computer, and allows the use of wildcard metacharacters to specify the filename.

mput filename

After modifying the /etc/aliases file, what command must be run in order to rebuild the aliases database?

newaliases

​What command can be used to see what actual time servers are being used for synchronization?

ntp_query

What PostgreSQL command-line utility backs up PostgreSQL database settings?

pg_dump

In NTP, what stratum consists of atomic devices or GPS clocks?

zero 0

What FTP command runs a shell on the local computer?

! explanation mark

What is the maximum number of characters that can be used in a NetBIOS name?

15

How can you specify the intended DNS server to query with the dig command?​

@server

When working with Sendmail, what command can be used to test SMTP support?

HELO

How does DHCP automatically configure IP addresses?

If your network interface is configured using DHCP, it sends a DHCP broadcast on the network requesting IP configuration information. If a DHCP server on the network has a range of IP addresses, it leases an IP address to the client computer for a certain period of time; after this lease has expired, the client computer must send another DHCP request. Because DHCP servers keep track of the IP addresses they lease to client computers, they can ensure that no two computers receive the same IP address. If two computers are accidentally configured manually with the same IP address, neither would be able to communicate using the IP protocol. DHCP servers can also send client computers other IP configuration information, such as the default gateway and the DNS server they should use.

What DNS resource record type is used to provide the IP address for the e-mail server for a zone?​

MX

What is NFS? How do you access files using a configured NFS Server?

Network File System (NFS) allows UNIX, Linux, and Macintosh OS X computers to share files transparently. In NFS, one computer shares (or exports) a directory in the directory tree by placing the name of that directory in the /etc/exports file. The other computer can then access that directory across the network by using the mount command to mount the remote directory on the local computer. To access files using NFS, you mount a directory from a remote NFS server on the network to a directory on your local computer. That is, you specify the NFS filesystem type, server name or IP address, remote directory, and local directory as arguments to the mount command. After running the mount command, you can use the /mnt directory as any other local directory, with all file operations performed in the /var directory on the remote computer. You can then dismount the NFS filesystem using the umount command.

The Apache daemon listens for HTTP requests on what port by default?

TCP 80

What is NIS? What is a master and slave NIS server? Give examples of configuration files that NIS is commonly used to coordinate.

You can use the Network Information Service (NIS) to coordinate common configuration files, such as /etc/passwd and /etc/hosts, across several Linux computers within an organization. Each computer that participates in NIS belongs to an NIS domain and uses an NIS map for accessing certain information rather than using the local configuration file. Furthermore, you can configure an NIS master server to send all NIS map configurations to NIS slave servers, which then distribute these NIS maps to all other Linux computers, known as NIS clients. Alternatively, a master NIS server can send NIS map configuration directly to NIS clients. ​ The most common configuration files that companies use NIS to coordinate across multiple systems are password databases (/etc/passwd and /etc/shadow). These allow users to log in to several different Linux servers using the same user name and password.

Which command below can be used at a BASH command prompt to obtain a web page?

curl

In order to change the time zone of a system after installation, what command must be used?​

tzselect