Chapter 11 - Secure Network

Question 1

Layer 7 Protocols

Answer 1

FTP, TFTP, SSH, IMAP, PCP, HTTP, HTTPS, LPD, SMTP, POP3, SNMP, DHCP

Question 2

Layer 6 Protocols

Answer 2

ASCII, EBCDICM, TIFF, JPEG, MPEG, MIDI

Question 3

Layer 5 Protocols

Answer 3

NFS, SQL, RPC

Question 4

Layer 4 Protocols

Answer 4

TCP, UDP, SPX, SSL, TLS

Question 5

Layer 3 Protocols

Answer 5

ICMP, RIP, OSPF, BGP, IGMP, IP, IPSec, IPX, NAT, SKIP

Question 6

Layer 2 Protocols

Answer 6

SLIP, PPP, ARP, RARP, L2F, L2TP, PPTP, ISDN

Question 7

Layer 1

Answer 7

• EIA/TIA-232 and EIA/TIA-449
	• X.21
	• High-Speed Serial Interface (HSSI)
	• Synchronous Optical Network (SONET)
V.24 and V.35

Question 8

Layer 1 Responsibilities

Answer 8

• Controls throughput rates
  
  • Handles synchronization
  • Manages line noise and medium access
  • Determines whether to use digital or analog signals or light pulses to transmit or receive data over the physical hardware interface

Question 9

Layer 2 Formats

Answer 9

○ Ethernet (IEEE 802.3)
		○ Token Ring (IEEE 802.5)
		○ Asynchronous Transfer Mode (ATM)
		○ Fiber Distributed Data Interface (FDDI)
Copper DDI (CDDI)

Question 10

Layer 4 Responsibility

Answer 10

managing the integrity of a connection and controlling the session.

Question 11

Layer 4 Mechanisms

Answer 11

○ Segmentation
		○ Sequencing
		○ Error checking
		○ Controlling data flow
		○ Error correction
		○ Multiplexing
Network service optimization

Question 12

Fiber Channel Over Ethernet (FCoE)

Answer 12

• Form of network data storage solution SAN or network attached storage (NAS) that allows for high-speed file transfers at upward of 16GB.
• Used to encapsulate fibre channel communications over ethernet.
• Typically requires 10 GB ethernet to support.
Network/Layer 3.

Question 13

Multiprotocol Label Switching (MPLS)

Answer 13

• High-throughput high-performance network tech that directs data across a network based on short path labels rather than longer network addresses.
  
  • Faster than IP
  • Handles lots of protocols

Question 14

Internet Small Computer System Interface (iSCSI)

Answer 14

• Networking storage standard based on IP.
• Can be used to enable location-independent file storage, transmission, and retrieval over LAN, WAN or Internet.
Low cost alternative to fibre channel.

Question 15

Antenna Types

Answer 15

○ Yagi - like TV antenna
○ Cantenna - tubes with one sealed end
○ Panel - flat devices that focus from only one side of panel
Parabolic - used to focus signals from very long distances or weak sources

Question 16

Static Firewall

Answer 16

• Examines data from message header
	• cant prform user auth or determine if packet is from inside or outside
	• 1st generation
	• Layer 3
Screening routers/common routers

Question 17

App Level Gateway Firewall

Answer 17

• Aka proxy firewalls
  
  • Proxy - mechanism the copies packets from one network into another, changes source and destination to protect identity of internal network
  • Filters traffic based on internet service (app) used to transmit or receive data.
  • Each type of app must have own proxy server
  • Negatively affects network performance because each packet is examined
  • 2nd gen
  • Layer 7

Question 18

Circuit Level Gateway Firewall

Answer 18

• Used to establish communication sessions between trusted partners
  
  • Session layer (5)
  • SOCKS (socketsecure) is common implementation.
  • Aka circuit proxies
  • Manage communications based on circuit rather than content.
  • 2nd gen

Question 19

Stageful Inspection Firewall

Answer 19

• Aka dynamic packet filtering
• Evaluate state or context of network traffic
• Grants broader range of access for authorized users and activities
• Actively watch for and block unauthorized users.
• 3rd gen
Layers 3 and 4

Question 20

Frequency Hopping Spread Spectrum (FHSS)

Answer 20

early implementation of spread spectrum. Sends only one frequency at a time.

Question 21

Direct Sequence Spread Spectrum (DSSS)

Answer 21

employs all available frequencies simultaneously. Higher data throughput than FHSS. Chipping code allows message to be constructed if pieces are missing.

Question 22

Orthogonal Frequency-Division Multiplexing (OFDM)

Answer 22

uses digital multicarrier modulation scheme that allows for more tightly compacted transmission. Signals are perpendicular not causing interference with each other. Requires smaller frequency set but has better data throughput.

Question 23

Synchronous

Answer 23

rely on timing or clocking mechanism based on either an independent clock or time stamp embedded in the data stream. Supports very high rates of data transfer.

Question 24

Asynchronous

Answer 24

reply on stop and start delimiter bit to manage transmission of data. Suited for smaller amounts of data. PSTN modems.