Module 4: Protocols

Which protocol's header would a layer 4 device read and process? a. IP b. TCP c. ARP (address resolution protocol) d. HTTP

b. TCP

What is the Internet standard MTU (maximum transmission unit)? a. 65,535 bytes b. 1,522 bytes c. 1,500 bytes d. 9,198 bytes

c. 1,500 bytes

At which OSI layer does IP operate? a. Application layer b. Transport layer c. Network layer d. Data link layer

c. Network layer

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? a. telnet 192.168.1.56 b. tracert 192.168.1.56 c. arp -a d. netstat -n

c. arp -a

What field in a TCP segment is used to determine if an arriving data unit exactly matches the data unit sent by the source? a. Source port b. Acknowledgement number c. DiffServ d. Checksum

d. Checksum

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

The preamble and SFD (start frame delimiter) fields are not included when calculating a frame's size, and sometimes not even the FCS (frame check sequence), as this data is removed from incoming transmissions by the hardware before it becomes visible to any but the most sophisticated capture tools.

Which encryption benchmark ensures data is not modified after it's transmitted and before it's received? a. Confidentiality b. Integrity c. Availability d. Symmetric

b. Integrity

What process is used to establish a TCP connection?

The three-way handshake process establishes a TCP connection. SYN (request for a connection); SYN/ACK (response to the request); ACK (connection established).

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

Private key encryption is also known as symmetric encryption because the same key is used during both the encryption and decryption of the data. Because public key encryption requires the use of two different keys, one to encrypt and the other to decrypt, it is also known as asymmetric encryption.

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 for information that could not be satisfied by data already in the ARP table. Static ARP table entries are those that someone has entered manually using the ARP utility.

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

OpenVPN can cross many firewalls where IPsec might be blocked.

What three characteristics about TCP distinguish it from UDP?

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

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

VNC (Virtual Network Computing) is similar in concept to RDP but uses the cross-platform protocol RFB (remote frame buffer) to remotely control a workstation or server... VNC is open source.

Which two protocols manage neighbor discovery processes on IPv4 networks? a. ICMP (internet control message protocol) and ARP (address resolution protocol) b. IPv4 and IPv6 c. TCP and UDP d. NDP (neighbor discovery protocol) and Ethernet

a. ICMP and ARP

Which remote file access protocol is an extension of SSH? a. SFTP (SSH File Transfer Protocol) b. TFTP (Trivial File Transfer Protocol) c. FTPS (File Transfer Protocol Secure) d. HTTPS (Hypertext Transfer Protocol Secure)

a. SFTP

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

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

The default port for using the Remote Desktop Protocol is 3389. This port should be open through Windows Firewall to make it RDP accessible within the local area network.

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?

The digital certificate is issued, maintained, and validated by an organization called a CA (certificate authority).

What is one advantage offered by VDI (virtual desktop infrastructure) over RDS (remote desktop services) and VNC (virtual network computing)? a. Offers access to multiple OSs in VMs b. Supports remote access to mobile devices c. Allows multiple users to sign in at once d. Provides open source flexibility

a. Offers access to multiple OSs in VMs

Which encryption protocol does GRE (generic route encapsulation) use to increase the security of its transmission? a. SSL b. SFTP c. IPsec d. SSH

c. IPsec