Which THREE of the following actions should be considered when a FTP chroot jail is created?

Connecting to a remote host on the same LAN using ssh public-key authentication works but
forwarding X11 doesn’t. The remote host allows access to both services. Which of the following
can be the reason for that behavior?

An iptables firewall was configured to use the target MASQUERADE to share a dedicated wireless
connection to the Internet with a few hosts on the local network.
The Internet connection becomes very unstable in rainy days and users complain their
connections drop when downloading e-mail or large files, while web browsing seems to be working
fine.
Which change to your iptables rules could alleviate the problem?

Which command line create an SSH tunnel for POP and SMTP protocols?

Which of these tools can provide the most information about DNS queries?

Which records must be entered in a zone file in order to use “Round Robin Load Distribution” for a web server?

Which command would release the current IP address leased by a DHCP server?

Remote access to a CD-RW device on a machine on a LAN must be restricted to a selected user
group. Select the TWO correct alternatives that describe the possible solutions for this problem.

Select the alternative that shows the correct way to disable a user login (except for root)

A new user was created on a master NIS server using useradd but cannot log in from an NIS client.
Older users can log in. Which step was probably forgotten, when creating the new user?