CompTIA XK0-005 Exam With Confidence Using Practice Dumps

The IP ping works, but DNS resolution fails, indicating that a DNS server is not configured properly in /etc/resolv.conf. That file is responsible for DNS resolution.

Source: CompTIA Linux+ XK0-005 Study Guide – Chapter 9: Networking

The users who have root-level command-line access are those who have either the same user ID (UID) as root, which is 0, or the ability to run commands as root using sudo. Based on the /etc/passwd and /etc/sudoers files, the users who meet these criteria are:

Carl: Carl has the same UID as root, which is 0, as shown in the /etc/passwd file. This means that Carl can log in as root and execute any command with root privileges1

Mallory: Mallory has the ability to run commands as root using sudo, as shown in the /etc/sudoers file. The line ALL = (ALL) ALL means that any user can run any command as any other user, including root, by using sudo. Mallory can also use the root shell /bin/bash as her login shell, as shown in the /etc/passwd file2

Therefore, the correct answer is A and C. Lee, Eve, Bob, and Alice do not have root-level command-line access because they have different UIDs from root and they cannot use sudo to run commands as root. Lee can only use sudo to run the commands listed in the Cmnd_Alias SHELLS, which are /bin/tcsh, /bin/sh, and /bin/bash. Eve cannot log in at all because her login shell is /bin/nologin. Bob and Alice can only use sudo to run the command /usr/sbin/tcpdump without a password, as specified by the Cmnd_Alias SYSADMIN and the line ALL = NOPASSWD: SYSADMIN2

mtr (My Traceroute) is a network diagnostic tool that combines the functionality of traceroute and ping. It shows real-time packet loss and latency on a hop-by-hop basis. The -T option uses TCP instead of ICMP, and the -P 443 option specifies the remote port. This provides the best method for checking packet loss on port 443.