Which of the following are two authentic public DNS server addresses?

Which of the following are two authentic public DNS server addresses?

• 8.8.8.8 & 8.8.4.4
• 8.8.2.2 & 8.8.4.4
• 8.8.8.8 & 8.8.2.2
• 8.8.8.8 & 8.8.8.7 

 

EXPLANATION

The two public DNS Server Addresses of 8.8.8.8 and  8.8.4.4 are Googles Public DNS Servers that are free for use.

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When it comes to email, what is Postfix?

When it comes to email, what is Postfix?

• A mail user agent
• Paid software
• A mail submission agent
• A mail transfer agent 

 

EXPLANATION

Postfix is a mail transfer agent (MTA), which handle the long-haul delivery of the mail to other MTAs. Postfix supports LDAP, SMTP AUTH (SASL), TLS, and running in a chroot environment.
 

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Grandfather-Father-Son (GFS) is a(n):

Grandfather-Father-Son (GFS) is a(n):

• Hierarchical UML design pattern
• Common backup media rotation strategy
• Inheritance design standard in object-oriented programming
• Layered SDN (software defined networking) design standard 

 

EXPLANATION

Grandfather-Father-Son is a common backup media rotation strategy. It employs a daily-weekly-monthly approach that addresses near-term and long-term (archival) backup concerns.
https://www.sans.org/reading-room/whitepapers/sysadmin/backup-rotations-final-defense-305

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If you’re looking to display all files in a given directory and all its sub-directories, including hidden files, which of the following Linux command would you use?

If you’re looking to display all files in a given directory and all its sub-directories, including hidden files, which of the following Linux command would you use?

• ls -aR
• ls -l
• ls-a
• ls -R 

 

EXPLANATION

The Bash command "ls" lists all information about a given file. In this case, it’s modified by "-aR" to maintain groups of files as a single archive file, which displays everything in a given file. By itself, this command will show you everything on your hard disk (and we mean everything).

SOURCE

http://linuxcommand.org/lc3_man_pages/ls1.html

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Which of the following is an IPV6 automatic tunneling protocol used by Windows on systems located behind a NAT router?

Which of the following is an IPV6 automatic tunneling protocol used by Windows on systems located behind a NAT router?

• APIPA
• ISATAP
• 6to4
• Teredo

 

EXPLANATION

Teredo is a mechanism that enables devices behind non-IPv6 NAT routers to function as tunnel endpoints.
For more information on Teredo, see: https://en.wikipedia.org/wiki/Teredo_tunneling
 

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