You want to change your email from your current hosting provider to Google Apps. What should you do to ensure the change does not take more than an hour?

You want to change your email from your current hosting provider to Google Apps. What should you do to ensure the change does not take more than an hour?

• Change the MX record to the ones provided by Google
• Change your NS records to Google IP address
• Create a new A record
• Check and lower the TTL 

 

EXPLANATION

It's always a very good idea to check and lower the Time-To-Live (TTL) for a domain to ensure that any changes made are propagated in a short time frame and your customers and boss remain happy. NOTE: TTL is normally specified in seconds, you need to divide by 60 to get minutes.
https://mediatemple.net/community/products/dv/204644120/understanding-ttl-(time-to-live)
In the end you will need to change the MX record, but changing the MX record does not change how quickly the change will happen.

 

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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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