Which of the following is not a system role in vCenter?

Which of the following is not a system role in vCenter?

• Administrator
• Read Only
• No Access
• Virtual Machine User (Power User) 

EXPLANATION

Virtual Machine User is a sample role on the vCenter system of permissions - No Access, Administrator and Read Only are the system roles which are not customizable.

SOURCE

https://pubs.vmware.com/vsphere-60/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-60-security-guide.pdf

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What is the maximum number of USB devices a host controller can handle?

What is the maximum number of USB devices a host controller can handle?

• 128
• 155
• 64
• 127 

 

EXPLANATION

At 7 bits long, a single USB Host Controller can allow up to 127 (2^7 – 1 Host Controller) connected devices.

USB hubs can be cascaded up to seven times, the maximum number of user devices is reduced by number of hubs. So, with 19 hubs attached, the maximum number of available devices is reduced 127 − 19 = 108.

SOURCE

https://en.wikipedia.org/wiki/USB_hub (Physical Layout section)

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What type of DNS record is used by the Sender Policy Framework (SPF)?

What type of DNS record is used by the Sender Policy Framework (SPF)?

• TXT
• MX
• A
• CNAME 

 

EXPLANATION

Sender Policy Framework (SPF) is a simple email-validation system designed to detect email spoofing. The SPF is an open standard specifying a technical method to prevent sender-address forgery. SPF allows administrators to specify which hosts are allowed to send mail on behalf of a given domain by creating a specific SPF record (or TXT record) in the Domain Name System (DNS). Mail exchangers use DNS records to check that mail from a given domain is being sent by a host sanctioned by that domain's administrators.

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What's a network segment for public-facing servers that's separated from a private, trusted network by a firewall?

What's a network segment for public-facing servers that's separated from a private, trusted network by a firewall?

• DMZ
• NSA
• VPN
• ATA 

EXPLANATION

A DMZ, or demilitarized zone, is a physical or logical subnetwork that contains and exposes an organization's external-facing services to a larger and untrusted network, usually the Internet. The purpose of a DMZ is to add an additional layer of security to an organization's local area network (LAN).

SOURCE

http://www.ciscopress.com/articles/article.asp?p=1823359

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To avoid data corruption, which of the following should you do before performing fsck on a file system?

To avoid data corruption, which of the following should you do before performing fsck on a file system?

• Reboot the machine
• Create a new data partition
• Unmount the file system
• Ensure the file system is mounted 

 

EXPLANATION

The fsck command is used to check and repair one or more Linux file systems. Running fsck on a mounted file system can cause data or disk corruption. Instead, you can do one of the following:
(a) Take down system to single user mode and unmount the system
(b) Boot from the installation CD

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