MODULE 4 Review Questions

When surfing online, you get some strange data on an apparently secure website, and you realize you need to check the legitimacy of the site. What kind of organization issues digital certificates for websites?

Certificate Authority

What field in a TCP segment is used to determine if an arriving data unit exactly matches the data unit sent by the source?

Checksum

What is the difference between dynamic ARP table entries and static ARP table entries?

Dynamic ARP table entries are created when a client makes an ARP request, whereas static ARP table entries are entered manually using the ARP utility.

Which two protocols manage neighbor discovery processes on IPv4 networks?

ICMP and ARP

Which encryption protocol does GRE use to increase the security of its transmissions?

IPsec

What is one advantage offered by VDI over RDS and VNC?

Offers access to multiple OS's in VMs

Which secured tunneling protocol might be able to cross firewalls where IPsec is blocked?

OpenVPN

What three characteristics about TCP distinguish it from UDP?

TCP is connection-oriented; it uses sequencing and checksums; and it provides flow control.

What process is used to establish a TCP connection?

TCP uses a three-way handshake to establish a reliable connection. The connection is full duplex, and both sides synchronize (SYN) and acknowledge (ACK) each other. The exchange of these four flags is performed in three steps—SYN, SYN-ACK, and ACK—as shown in Figure 3.8. Figure 3.8.

What is the Internet standard MTU?

The common value of MTU on the internet is 1500 bytes.

Explain the key difference between how symmetric encryption works and how asymmetric encryption works.

Asymmetric encryption is also known as public-key encryption. It uses two different keys to encrypt messages: the public key and the private key. Symmetric encryption is different because it uses only one key to encrypt and decrypt messages. Symmetric encryption is much faster for the computer to process, but it raises the costs of key management.In symmetric encryption, also called private key encryption, the same key is used both to encrypt and decrypt the message. Both the sender and receiver must own encryption of the key. The problem with symmetric encryption is getting a copy of the key to the sender.Asymmetric encryption uses two different keys. Either key may encrypt or decrypt the message, but one key must be used for encryption only and the other must be used for decryption only. The technique has the greatest value when one key is used as a private key and the other is used as a public key. The public key is stored in a public location where anyone can use it. The problem wi

Which encryption benchmark ensures data is not modified after it's transmitted and before it's received?

Integrity

Which two fields in an Ethernet frame help synchronize device communications but are not counted toward the frame's size?

Preamble and SFD (start frame delimiter) fields help synchronize device communication but are not counted toward the frame's size.

Which remote file access protocol is an extension of SSH?

SFTP

Which protocol's header would a layer 4 device read and process?

TCP

Which terminal emulation protocol is similar to RDP but is open source?

VNC (Virtual Network Computing or Virtual Network Connection) uses the cross-platform protocol RFB (remote frame buffer) to remotely control a workstation or server.

You're getting a duplicate IP address error on your computer and need to figure out what other device on your network is using the IP address 192.168.1.56. What command will show you which MAC address is mapped to that IP address?

arp -a

What tcpdump command will capture data on the eth0 interface and redirect output to a text file named checkme.txt for further analysis?

tcpdump -i eth0 -w checkme.txt

At which OSI layer does IP operate? a. Application layer

network layer

Which port must be open for RDP traffic to cross a firewall?

port 3389