Communications and Network Security (CNS) Flashcards
Access point
the connection between a wireless and wired network
Access server
Provides dial-in and dial-out connections to the network
Ad hoc Mode
Directly connect two+ clients, no access point Infrastructure Mode – connects endpoints to a central network, not directly to each other, need access point and wireless clients for IM mode wireless
Address Resolution Protocol
Used to match an IP address to a hardware MAC address. ARP sends out broadcast to a network node to reply with its hardware address. It stores the address in a dynamic table for the duration of the session, so ARP requests are only sent the first time
Addressing
IP uses the destination IP to transmit packets thru networks until delivered
ADSL
Asymmetric. More downstream bandwidth up to 18,000 feet over single copper cable pair
Analog signal
Infinite wave form, continuous signal, varied by amplification
Asynchronous communications, broadband connections, and half‐duplex links can be digital or analog.
Application
Layer 4 network
Application OSI
Provides an interface for which applications and end users can utilize networked resources.
Examples: FTP, Telnet
Application level firewall
Second generation: AKA proxy server While transferring data stream to another network, it masks the data origin. operating at Application layer of OSI
Application Proxy firewall
Layer 7: actually 3 through 7, which look at content and can involve authentication and encryption, can be more flexible and secure but also tend to be far slower.
ARCnet
Uses token passing in a star technology on coax
Asymmetric multiproccessing
AMP: used in applications that are dedicated, such as embedded systems, when individual processors can be dedicated to specific tasks at design time
Asynchronous
Sends bits of data sequentially. Same speed on both sides. Modems and dial-up remote access systems
Asynchronous Transfer Mode
ATM: very high bandwidth. It uses 53-byte fixed size cells instead of frames like Ethernet. It can allocate bandwidth up on demand making it a solution for Busty applications. Requires fiber optics
Attenuation
A decrease in amplitude as a signal propagates along a transmission medium
Access port
logical or physical identifier that a computer uses to distinguish different terminal input/output data streams
Active attack
attack on the authentication protocol where the attacker transmits data to the claimant or verifier. Examples of active attacks include a man-in-the-middle, impersonation, and session hijacking.
Active wiretapping
illegal attaching of an unauthorized device for the purpose of obtaining access to data
Bluejacking
When attackers send unsolicited messages via Bluetooth
Bluesnarfing
Targets the data or information on Bluetooth-enabled devices
Bootstrap Protocol
When wireless workstation is on-lined it sends out a BootP request with its MAC address to get an IP address and the file from which it should boot. Replaced by DHCP
Bridge
a layer 2 device that used to connect two network segments and regulate traffic
Bridges
Forwards data to all other network segments if it’s not on the local segment. Operates at level 2 (thus no IP-addressing)
Broadband Technologies
ISDN, cable modems, DSL, and T1/T3 lines that can support multiple simultaneous signals. They are analog and not broadcast technologies.
Broadcast
Source packet is copied and sent to all nodes
Broadcast Domain
Set of systems that can receive a broadcast from each other
Brouter
a device that provides the functions of both a bridge and a router
BUS
All transmissions have to travel the full length of the cable
Callback
User initiates a connection, supplies identifying code, and then the system will call back a predetermined telephone number. Also less useful for travelling users
Caller ID
Checks incoming telephone number against an approval list and then uses Callback. Less useful for travelling users
CAN
Campus area network: multiple building connected to fast backbone on a campus
Carrier Sense Multiple Access
CSMA: for Ethernet. Workstations send out packet. If it doesn’t get an acknowledgement, it resends
Challenge Handshake Authenticate Protocol
CHAP: non-replayable challenge/response dialog
CHAP
Challenge-Handshake Authentication Protocol, used by PPP servers to authenticate remote clients. Encrypts username and PW and performs periodic re authentication while connected using techniques to prevent replay attacks.
CIR
Committed Information Rate: minimum bandwidth guarantee provided by service provider to customers
Circuit Level Proxy
Layer 5: looks at header of packet only, protects wide range of protocols and services than app-level proxy, but as detailed a level of control. Basically once the circuit is allowed all info is tunneled between the parties. Although firewalls are difficult to configure correctly, they are a critical component of network security.
Circuit switched network
There must be a dedicated physical circuit path exist during transmission. The right choice for networks that have to communicate constantly. Typically for a telephone company network Voice oriented. Sensitive to loss of connection
Client SSL Certificates
Used to identify clients to servers via SSL (client authentication)
Coaxial
Many workstations, length. 1000Base-T – 100 M
Twisted pair to long. Cat 5 better than cat3 for interference Fiber optics immune to EMI, can be broken and high cost/expertise Topology failures
Coaxial cable
a cable consisting of a core, inner conductor that is surrounding by an insulator, an outer cylindrical conductor
Codec
used to code/decode a digital data stream
Collision Domain
Set of systems that could cause a collision if they transmitted at the same time, more number of systems in domain increases likelihood of network congestion due to more collisions
Concentrator
layer 1 network device that is used to connect network segments together, but provides no traffic control
Converged Network
Carries multiple types of traffic like voice, video, and data
Converged Protocols
The merging of specialty or proprietary protocols with standard protocols, such as those from the TCP/ IP suite. The primary benefit of converged protocols is the ability to use existing TCP/ IP supporting network infrastructure to host special or proprietary services without the need for unique deployments of alternate networking hardware.
CSMA with Collision Avoidance workstations
z- are attached by 2 coax cables. In one direction only. Wireless 802.11
CSMA with Collision Detection
Only one host can send at the time, using jamming signals for the rest
Data Link Layer 2
z-C
This layer deals with addressing physical hardware. FRAMES
Translates data into bits and formats them into data frames with destination header and source address. Error detection via checksums.
Example: bridge
Data service unit (DSU)
z-also Channel Service Unit (CSU)
Digital interface device, used to terminate the physical interface on a DTE device. They connect to the closest telephone company switch in a central office (CO)
Data Streams
Occur at Application, Presentation, and Session layers.
Demon Dialer
a technique by which a computer is used to repeatedly dial a number (usually to a crowded modem pool) in an attempt to gain access immediately after another user had hung up
DHCP
z-Dynamic Host Configuration Protocol
Digital signal
Saw tooth form, pulses, on-off only, digital signals are a means of transmission that involves the use of a discontinuous electrical signal and a state change or on‐off pulses. Asynchronous communications, broadband connections, and half‐duplex links can be digital or analog.
Digital signature
an asymmetric cryptography mechanism that provides authentication
Direct Sequence Spread Spectrum
DSSS: employs all the available frequencies simultaneously in parallel. This provides a higher rate of data throughput than FHSS. DSSS also uses a special encoding mechanism known as chipping code to allow a receiver to reconstruct data even if parts of the signal were distorted because of interference.
DKIM
Domain Keys Identified Mail, domain validation tool
DNS Poisoning
When an attacker changes the domain name to IP address mappings of a system to redirect traffic to alternative systems
DNS Spoofing
When an attacker sends false replies to a requesting system, beating valid replies from the real DNS server
Dual homed host firewall
Consists of a host with 2 NIC’s. One connected to trusted, one to un-trusted. Can thus be used as translator between 2 network types like Ethernet/token ring. Internal routing capabilities must not be enabled to make it impossible to circumvent inspection of data.
Dynamic Packet Filtering firewall
Fourth generation: Enables modification of the firewall rule. It provides limited support for UDP by remembering UDP packages across the network.
Eavesdropping
a passive network attack involving monitoring of traffic
E-mail spoofing
forgery of the sender’s email address in an email header
Emanations
potentially compromising leakage of electrical or acoustical signals
Encapsulating Security Payload
z-Encrypts IP packets and ensured integrity.
ESP Header – contains information showing which security association to use and the packet sequence number. Like the AH, the ESP sequences every packet to thwart replay attacks.
Ethernet IEEE 802.3
Using CSMA with an BUS-topology
Ethernet twisted pair
More resistant than coaxial Token Ring because a token is passed by every station, a NIC that’s is set to wrong speed or error can take all network down
Extensible Authentication Protocol
EAP: an authentication framework. Allows for new authentication technologies to be compatible with existing wireless or point-to-point connection technologies, extensible was used for PPP connections
Faraday Cage/ Shield
A shield against leakage of electromagnetic signals.
Fiber Channel Over Ethernet
FCoE: allows existing high-speed networks to be used to carry storage traffic
Fiber Distributed Data Interface
Form of token ring that has second ring that activates on error
Leased lines use multiple lines and/or multiple vendors
Fiber optics
bundles of long strands of pure glass that efficiently transmit light pulses over long distances. Interception without detection is difficult.
Fibre Channel over Ethernet
z-FCoE: a form of network data-storage solution (SAN or NAS) that allows for high-speed file transfers at upward of 16 GBps. It was designed to be operated over fiber-optic cables; support for copper cables was added later to offer less-expensive options. (FCoE) can be used to support it over the existing network infrastructure. FCoE is used to encapsulate Fibre Channel communications over Ethernet networks. Fibre Channel operates as a Network layer or OSI layer 3 protocol, replacing IP as the payload of a standard Ethernet network.
File Transfer Protocol
For file transfers. Cannot execute remote files as programs. Authentication. Port 20 and 21
Firewalls
a group of systems that enforces an access control policy between two networks
Fraggle
a denial of service attack initiated by sending spoofed UDP echo request to IP broadcast addresses
Fragmentation
z- DEAN plz note, there is an entry called “IP fragmentation,” but this appears to be a different definition / concept
IP will subdivide a packet if its size is greater than the maximum allowed on a local network
Message routing, error detection and control of node data are managed. IP, IPSEC, ICMP, BGP, OSPF, RIP, BOOTP, DHCP, ZIP, DDP, X.25, NAT and IGMP
Frame Relay
High performance WAN protocol designed for use across ISDN interfaces. Is fast but has no error correction, supports multiple PVCs, unlike X.25, packet switched technology that provides CIR, requires DTE/DCE at each connection point
Frame Relay WAN
Over a public switched network. High Fault tolerance by relaying fault segments to working.
Frequency Hopping Spread Spectrum
FHSS: The entire range of available frequencies is employed, but only one frequency at a time is used.
Gateway
a secure connection to another network
HDSL
High Rate T1 speed over two copper cable pairs up to 12,000 feet
High-level Data Link Control
HDLC: extension to SDLC also for mainframes. Uses data encapsulation on synchronous serial links using frame characters and checksums. Also data link layer High Speed Serial Interface (HSSI) - Defines electrical and physical interfaces to use for DTE/DCE communications. Physical layer of OSI
Hijacking
interception and take over of a communication session by an attacker
Host-to-Host
Layer 3 (Transport)
Hub
layer 1 network device that is used to connect network segments together, but provides no traffic control
HUBS
Connect multiple LAN devices into a concentrator. Is actually a multi-port repeater (physical)
Hypervisor-based Network
May be software defined, but it could also use traditional network devices running as virtual machines
Injection
an attack technique that exploits systems that do not perform input validation by embedding partial SQL queries inside input
Integrated Services Digital Network
ISDN: combination of digital telephony and data transports. Overtaken by xDSL, not all useable due to “D Channel” used for call management not data
Interception
unauthorized access of information (e.g. tapping, sniffing, unsecured wireless communications, emanations)
Internet
Layer 2 (corresponds to OSI network layer) Defines the IP datagram and handles routing of data across networks
Protocols: IP, ARP, RARP, ICMP
Internet control message protocol
Sends messages between network nodes regarding the health of the network. Also informs about rerouting in case of errors. Utility PING uses ICMP messages to check physical connectivity of the network machines
IPX, Appletalk, and NetBEUI are non-IP protocols
Internet intranet and extranet
Internet is global, intranet local for use within companies and extranet can be used e.g. by your customers and clients but is not public.
Internet Protocol
z-All hosts have an IP address. Each data packet has an IP address of sender and recipient. Routing in network is based upon these addresses. Datagram service is considered unreliable because there’s no guarantee that the packet will be delivered, not even that its delivered only once and no guarantee that its delivered in the same sequence that its sent
32 bits long, IPv6 is 128 bits long
Internet Small Computer Interface
iSCI: Converged protocol that allows location-independent file services over traditional network technologies. Cost less than Fiber. Standard for linking data storage sites
Internet Small Computer System Interface
iSCSI: a networking storage standard based on IP. This technology can be used to enable location-independent file storage, transmission, and retrieval over LAN, WAN, or public Internet connections.
It is often viewed as a low-cost alternative to Fibre Channel.
IP address spoofing
forging of an IP address
IP fragmentation
an attack that breaks up malicious code into fragments, in an attempt to elude detection
IPSEC
z-Operates at Network Layer of OSI
Enables multiple and simultaneous tunnels
Encrypt and authenticate
Build into IPv6
Network-to-network use
Creates a private, encrypted network via a public network
Encryption for confidentiality and integrity
IPSEC compatible
Encryption via Tunnel mode (entire data package encrypted) or Transport mode (only datagram encrypted)
Only works with IP at Network layer of OSI NON IP-sec compatible
ISDN
PRI (Primary Rate Interface) bandwidth of 1.544 Mbps, faster than BRI’s 144 Kbps
Kernel Proxy Firewall
Fifth generation: Application level Firewall Runs in windows NT, modular, kernel based, multiplayer session evaluation. Uses dynamic TCP/IP stacks to inspect network packages and enforce security policies.
L2F, Layer 2 Forwarding
z-Cisco developed its own VPN protocol called which is a mutual authentication tunneling mechanism.
L2F does not offer encryption. L2F was not widely deployed and was soon replaced by L2TP. Both operate at layer 2. Both can encapsulate any LAN protocol.
L2TP, Layer 2 tunneling protocol
z-Also in data-link layer of OSI
Single point-to-point connection per session
Dial-up network use
Port 115
Uses IPsec
LAN extenders
Remote access, multi layer switch that connects LANs over a WAN
Land Attack
Involves sending a spoofed TCP SYN packet (connection initiation) with the target host’s IP address and an open port as both source and destination.
The reason a LAND attack works is because it causes the machine to reply to itself continuously.
LDAP
Lightweight Directory Access Protocol, client/server based directory query protocol loosely based upon X.500, commonly manages user information, for accessing directory services and manage certificates Ex. Active Directory, cn=ben+ou=sales
Zero or more, comma separated, no semi-colon, + to join
LEAP
Lightweight Extensible Authentication Protocol, Cisco proprietary protocol to handle problems with TKIP, security issues don’t use. Provides reauthentication but was designed for WEP
Link Access Procedure-Balanced
(LAPB) created for use with X25, defines frame types and is capable of retransmitting, exchanging and acknowledging frames as detecting out of sequence or missing frames
Local Area Network
LAN: Limited geographically to e.g. a building. Devices are sharing resources like printers, email and files. Connected through copper wire or fiber optics.
Logical Link Control Sub layer
Flow control and error notification
Machine Access Control
MAC: hardware address of machine, can tell manufacturer,
MAN
z-Metropolitan network extends over cities DEAN, is the word “area” missing here?
Media Access Control layer
z-Physical addressing. Concerns frames, logical topologies and MAC-addresses
Protocols: L2F, PPTP, L2TP, PPP, SLIP, ARP, RARP, SLARP,
IARP, SNAP, BAP, CHAP, LCP, LZS, MLP, Frame Relay, Annex
A, Annex D, HDLC, BPDU, LAPD, ISL, MAC,
Ethernet, Token Ring, FDDI
MESH
All nodes interconnected
Message switching networks
Involves the transmission of messages from node-to-node. Messages are stored on the network until a forwarding path is available.
Microwave
high frequency, highly directional radio signals. Attackers target interception attempts at transmission and relay stations.
Modems
a device that converts between digital and analog representation of data
Modification
a type of attack involving attempted insertion, deletion or altering of data
MOSS
MIME Object Security Services, provides authentication, confidentiality, integrity, and nonrepudiation
Multicast
Source packet is copied and sent to multiple destinations
Multilayer Protocols
Allow encryption at various layers, support a range of protocols at higher levels. Bad – conceal covert channels, filters can be bypassed, sometimes logical boundaries can be bypassed
Multiplexers
a device that sequentially switches multiple analog inputs to the output
Multiprotocol Label Switching
MPLS: high performance networking, uses path labels instead of network addresses, wide area networking protocol, label switching, finds final destination and then labels route for others to follow
Network access
Layer 1 (Data link, Physical)
Routines for accessing physical networks and the electrical connection
Network File System
Protocol that supports file sharing between two different file systems
Network Layer 3
z-C, AU, I
Path selection and logical/network addressing.
Technology: Virtual circuits (ATM), routers. Packets
Example: router
Network layers TCP/IP Model
z-Developed by Department of Defense in the 1970s to support the construction of the internet
HINT: AHIN
OAuth
Ability to access resources from another service
Open mail relay servers
a mail server that improperly allows inbound SMTP connections for domains it does not serve
Open Shortest Path First
z-Routing protocol short path
OpenID
Paired with OAuth is a RESTful, JSON-based authentication protocol can provide identity verification and basic profile information, phishing attack possible by sending fake data
OpenLDAP
Default, stores user PW in the clear
Orthogonal Frequency-Division Multiplexing
OFDM: employs a digital multicarrier modulation scheme that allows for a more tightly compacted transmission. The modulated signals are perpendicular and thus do not cause interference with each other.
Overlapping fragment attack
a denial of service attack that exploits packet filter firewalls that only inspect the initial fragment of a fragmented packet
Packet filtering
a basic level of network access control that is based upon information contained in the IP packet header
Packet filtering firewall
First generation (static) AKA screening router Examines source/destination address, protocol and ports of the incoming package. Based on ACL’s access can be denied or accepted. Is considered a firewall and operates at Network or Transport layer of OSI
Packet filtering routers
Sits between trusted and un-trusted network, sometimes used as boundary router. Uses ACL’s. Protects against standard generic external attacks. Has no user authentication, has minimal auditing.
Packet switched networks
PSN or PSDN: Nodes share bandwidth with each other by sending small data units called packets. Packets will be send to the other network and reassembled. Data oriented. Sensitive to loss of data. More cost effective than circuit switching because it creates virtual circuits only when they are needed.
Packet-filtering firewalls
layer 3/4 : use rules based on a packet’s source, destination, port or other basic information to determine whether or not to allow it into the network.
Password Authenticate Protocol
PAP: Provides identification and authentication of the user using static replayable passwords. No encryption of user-id or password during communication
Password Authentication Protocol
PAP: sends PW unencrypted
Patch panels
provides a physical cross connect point for devices
PBX
A Private Branch Exchange is a telephone exchange for a specific office or business
PEAP
Provides encryption for EAP methods and can provide authentication, does not implement CCMP, encapsulates EAS in a TLS tunnel
PEM
Provides authentication, confidentiality, integrity, and nonrepudiation
Permanent virtual circuits
PVC: like a dedicated leased line; the logical circuit always exists and is waiting for the customer to send data. Like a walkie-talkie
Phishing
a social engineering attack that uses spoofed email or websites to persuade people to divulge information
Physical Layer 1
z- C
Physical signaling. Coverts bits into voltages or light impulses. Electrical, Hardware and software drivers are on this level. It sends and receives bits.
Repeaters, hubs, cables, USB, DSL, ISDN, ATM
Physical topologies: BUS, MESH, STAR, TREE, RING
Physical tampering
unauthorized access of network devices
Point to Point Protocol
PPP: improvement on slip, adds login, password and error (by CHAP and PAP) and error correction. Data link.
Point-to-Point Protocol
PPP: Most common, used for dial up connections, replaced SLIP
Polling
Host can only transmit when he polls a secondary to see if its free
Port Based Authentication
802.1x, can be used with EAP
PPTP, Point to Point tunneling protocol
z-Works at data link layer of OSI
Only one single point-to-point connection per session
Point To Point protocol (PPP) for authentication and tunneling
Dial-up network use
Does not support EAP
Sends initial packets in plaintext
Presentation Layer 6
z-C, AU, Encryption
Translations like EBCDIC/ANSI; compression/decompression and encryption/decryption. Uses a common format to represent data, Standards like JPEG, TIFF, MID, HTML; Technology: Gateway.
Messages
Proxies
mediates communication between un-trusted hosts on behalf of the hosts that it protects
Proxy
Form of gateway that provide clients with a filtering, caching, or other service that protects their information from remote systems
PVCs
z-Private Virtual Circuits
RDP
z-Provides terminal sessions w/out
Repeaters
layer 1 network device that is used to connect network segments together, but provides no traffic control (a concentrator).
Restricted Address
Incoming calls are only allowed from specific addresses on an approval list. This authenticates the node, not the user!
Reverse address resolution protocol
When a hardware address is known but the IP address has to be found. (like an diskless machine)
Switches, bridges, hardware addressing
RING
Workstations are connected to form a closed loop
Rogue access points
unauthorized wireless network access device
Routers
a layer 3 device that used to connect two or more network segments and regulate traffic
RST flag
Used to reset or disconnect a session, resumed by restarting the connection via a new three-way handshake
S/MIME Certificates
Used for signed and encrypted emails, can form sign, and use as part of a SSO solution
Satellite
a specialized wireless receiver/transmitter placed in orbit that facilitates long distance communication
Screened-Host firewall system
Has both a packet-filter router and a bastion host. Provides both network layer (package filtering) as application layer (proxy) server.
Screenscraper
Copy actual screen, subset of remote control
SDN
z-Unique approach to network operation, design, and management. Aims at separating the infrastructure layer (i.e., hardware and hardware-based settings) from the control layer (i.e., network services of data transmission management). Furthermore, this also removes the traditional networking concepts of IP addressing, subnets, routing, and so on from needing to be programmed into or be deciphered by hosted applications. Offers a new network design that is directly programmable from a central location, is flexible, is vendor neutral, and is open-standards based.
SDSL
Symmetric up to 10,000 feet over single copper cable pair
Secure Electronic Transaction
Authentication for credit card transactions. Overtaken by SSL
Also uses message authentication code for integrity checking.
Secure Shell
Authentication, compression, confidentiality and integrity.
Uses RSA certificates for authentication and triple DES for encryption
Secure Socket Layer
Encryption technology to provide secure transactions like credit card numbers exchange. Two layered: record protocol and handshake protocol. Same as SSH it uses symmetric encryption for private connections and asymmetric or public key cryptography for peer authentication.
Security Perimeter
z-The first line of protection between trusted and untrusted networks. Generally includes a firewall and router that help filter traffic. May also include proxies, IDSs, and IPSs.
Zero Day – application white list
Sequence Attacks
An attack involving the hijacking of a TCP session by predicting a sequence number.
Session Layer 5
z- – None
Inter-host communication, logical persistent connection between peer hosts, a conversation, simplex, half duplex, full duplex. Protocols as NSF, SQL, RADIUS, and RPC. Protocols: PAP, PPTP, RPC Technology: Gateway
Examples: DNS, NFS
Shielding
Enclosure of electronic communication devices to prevent leakage of electromagnetic signals.
SHTTP
Encrypting HTTP documents. Also overtaken by SSL
Simple Key Management for Internet Protocols
Provides high availability in encrypted sessions to protect against crashes. Exchanges keys on a session by session basis.
Simple Mail Transfer protocol
Email queuing. Port 25
Simple Networking Management Protocol
Collection of network information by polling the devices from a management station. Sends out alerts –called traps- to an database called Management Information Bases (MIBs)
Site Survey
Identify areas where wireless network may be accessible
Smurf
A Denial of Service attack initiated by sending spoofed ICMP echo request to IP broadcast addresses
Screened-subnet firewalls
Has also defined a De-Militarized Zone (DMZ) : a small network between trusted an untrusted
Sequence attacks
an attack involving the hijacking of a TCP session by predicting a sequence number
Sniffing
eavesdropping on network communications by a third party
Socks firewall
Every workstation gets some Socks software to reduce overhead
Software designed networking
SDN: defined and configured as code or software, quickly change the network based on organizational requirements
SONET
Protocol for sending multiple optical streams over fiber
Source routing exploitation
a vulnerability in IP that allows an attacker to dictate the path of a communication and thereby access an internal network
Spam
unsolicited commercial email
Speeds
T-1 – 1.544 Mbps, T-3 – 44,736 Mbps (45)
ATM – 155 Mbps, ISDN – 64 or 128 Mbps
CAT 3 UTP; 10 Mbps, CAT 5;100 Mbps CAT 5e/6 – 1,000 Mb
SPIT attacks
Spam over Internet Telephony and targets VoIP systems
SSID
Normally disabled for secure networks
Stand-alone Mode
Isolated system
STAR
Nodes are connected to a central LAN device
Stateful inspection firewall
Third generation: (also known as Dynamic) All packages are inspected at the Networking layer so it’s faster. By examining the state and context of the data packages it helps to track connectionless protocols like UDP and RPC. Analyzed at all OSI Layers.
Stateful packet filtering firewalls
Layer 7 : have access to information such as; conversation, look at state table and context of packets; from which to make their decisions.
Static Packet Firewall
z- Layer 3
SUBNET
Logical division of a network
Supernet
Made up of two or more networks
Switched Multimegabit DATA Service
SMDS: high speed communication over public switches networks for exchanging
‘bursts of data’ between enterprises
Switched Virtual Circuit
SVC: more like a shortwave or ham radio. You must tune the transmitter and receiver to a new frequency every time you want to communicate with someone.
Switches
a layer 2 device that used to connect two or more network segments and regulate traffic
Symmetric Multiprocessors
SMP: hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all I/O devices, and are controlled by a single operating system instance that treats all processors equally, reserving none for special purposes.
SYN flooding
a denial of service attack that floods the target system with connection requests that are not finalized
Synchronous
Very high speed governed by electronic clock timing signals
Synchronous Data Link Control
SDLC: created by IBM for mainframes to connect to their remote offices. Uses a polling media access method. Works with dedicated leased lines permanent up.Data link layer of OSI model
tapping
eavesdropping on network communications by a third party
Tar pits
mitigation of spamming and other attacks by delaying incoming connections as long as possible
TCP Three-way Handshake
SYN, SYN-/ACK, ACK
Protocols: TCP, UDP, SSL, SSH-2, SPX, NetBIOS, ATP
Teardrop
a denial of service attack that exploits systems that are not able to handle malicious, overlapping and oversized IP fragments
Telnet
Terminal emulation enables user to access resources on another machine. Port 23
TEMPEST
a codename that refers to the study and mitigation of information disclosure via electromagnetic emanations from electronic equipment
Thicknet
10Base5, coax up to 500 meters
Thinnet
10base2 with coax cables up to 185 meters
Tiers
z-Design separates distinct protected zones and can be protected by a single firewall that has multiple interfaces
TKIP
Temporal Key Integrity Protocol, uses RC4
Token passing
Used in token rings, Hosts can only transit when they receive a clear to send token. DATA NETWORK TYPES
Token Ring IEEE 802.5
IBM created. All end stations are connected to a MAU Multi Access Unit. CAU: Controlled Access Units – for filtering allowed MAC (Extended Unique Identifier) addresses.
Transmission control protocol
z-Reliable, sequences and works with acknowledgements. Provides a manageable data flow to avoid congestions overloading and data loss. (Like having a telephone conversation with someone). Connection Oriented. User UDP, Datagram protocol – unreliable, scaled down version of TCP, no error correction, no sequencing. Less overhead. (Like sending a letter to someone). Connectionless.
Transport Layer 4
z- C, AU, I
End-to-end data transfer services and reliability. Technology:
Gateways. Segmentation, sequencing, and error checking at this layer. Datagrams
Examples: TCP which uses IP in network layer, UDP, SSH
Transport Layer Security
z-TLS: encrypt and protect transactions to prevent sniffing while data is in transit along with VPN and IPsec
most effective control against session hijacking
ephemeral session key is used to encrypt the actual content of communications between a web server and client
TLS - MOST CURRENT not SSL!!!
TREE
Bus type with multiple branches
Trivial File Transfer Protocol
Stripped down, can only send/receive but not browse directories. No authentication thus insecure. Port 69
Twisted pair
a simple, inexpensive cabling technology consisting of two conductors that are wound together to decrease interference
Types of Wireless Networks
z-Uses the 802.11x specification to create a wireless LAN
Unicast
Packet is sent from single source to single destination
User Datagram Protocol
UDP: lightweight service for connectionless data transfer without error detection and correction
UTP
10BaseT=10MBps
100baseT=Fast Ethernet =100MBps
1000BaseT=Gigabit Ethernet=1GBps
Ethernet networks were originally designed to work with more sporadic traffic than token ring networks
Valid Subnet Masks
255,254,252,248,240,224,192,128
VDSL
Very High speed 13-52MBps down, 1,5-2,3 Mbps upstream over a single copper pair over 1,00 to 4500 feet
Virtual Private Networks VPN
Created by dynamically building a secure communications link between two nodes, using a secret encapsulation method via network address translation (NAT) where internal IP addresses are translated to external IP addresses. Cannot double NAT with the same IP range, same IP address cannot appear inside and outside of a NAT router.
Voice over IP
Voice over Internet Protocol (VoIP) - a protocol for the efficient transmission of voice over the Internet
VPN Devices
Hardware or software to create secure tunnels
WAF
z-Web Application Firewall
WAN switches
Multi-port networking devices that are used in carrier networks. Connect private data over public data by using digital signals. Data link layer.
War dialing
reconnaissance technique, involving automated, brute force identification of potentially vulnerable modems
War driving
searching for wireless networks in a moving car
Wi-Fi
wireless local area network technology specified in the 802.11 sub group A, B, G, or N
WI-MAX
“Worldwide Interoperability of Microwave Access” (IEEE 802.16) is a specification for wireless Metropolitan Area Networks that provides an alternative to the use of cable and DSL for last mile delivery
Wide Area network
WAN: Connects LANS over a large geographical area
Wired Extension Mode
Uses WAP to link wireless clients to a wired network
Wireless speeds
Wi-Fi 6E (802.11ax), Max Linkrate = 600 to 9608 Mbit/s, Adopted = 2020, Frequency = 6 GHz
Wi-Fi 6 (802.11ax), Max Linkrate = 600 to 9608 Mbit/s, Adopted = 2019, Frequency = 2.4/5 GHz
Wi-Fi 5 (802.11ac), Max Linkrate = 433 to 6933 Mbit/s, Adopted = 2014, Frequency = 5 GHz
Wi-Fi 4 (802.11n), Max Linkrate = 72 to 600 Mbit/s, Adopted = 2008, Frequency = 2.4/5 GHz
(Wi-Fi 3)* 802.11g, Max Linkrate = 6 to 54 Mbit/s, Adopted = 2003, Frequency = 2.4 GHz
(Wi-Fi 2)* 802.11a, Max Linkrate = 6 to 54 Mbit/s, Adopted = 1999, Frequency = 5 GHz
(Wi-Fi 1)* 802.11b, Max Linkrate = 1 to 11 Mbit/s, Adopted = 1999, Frequency = 2.4 GHz
(Wi-Fi 0)* 802.11, Max Linkrate = 1 to 2 Mbit/s, Adopted = 1997, Frequency = 2.4 GHz
WPA
Uses TKIP for data encryption
WPA2
Based on 802.11i, uses AES, key management, reply attack protection, and data integrity, most secure, CCMP included, WPA2 ENTERPRISE Mode - uses RADIUS account lockout if a password-cracker is used
X25
Defines point-to-point communication between Data terminal Equipment (DTE) and Data Circuit Terminating Equipment (DCE)
xDSL
Digital subscriber Line uses telephone to transport high bandwidth data to remote subscribers
zero trust
organizations should not automatically trust anything inside or outside its perimeters and instead must authenticate and verify all subjects, objects, and actions before granting access
OSI Layer 1
Physical - Responsible for transmission of bits. Implemented primarily through hardware. Encompasses signaling method, electrical and mechanical interfaces
Devices = access point, concentrator/patch panel, hub, multiplexers, modem, repeater
Protocol = EIA-TIA 534
Security Protocol =
Attacks = Physical
OSI Layer 2
Data Link = responsible for error-free, reliable, transmission of data. Flow control, error detection and correction, retransmission. Uses MAC addresses.
Devices = bridge, switch
Protocol = X.25, Frame Relay, Asynchronous Transfer Mode (ATM), DOCSIS, Multi Protocol Label Switching (MPLS), Generic MPLS
Security Protocol =
Attacks = Physical
OSI Layer 3
Network = Transport of information. Abstraction of routing information. Not needed on direct links.
Devices = router
Protocol =
Routing->Authenticated(BGP, OSPF)
Routing->Unauthenticated(Routing Information Protocol, RIP, routing table compromise)
Network->Internet Protocol (IP)->IPv4
Network->Internet Protocol (IP)->IPv6
Network->Not answers->IPX (Novell), DRP (DECnet), DDP, (AppleTalk), CLNP (ISO)
Testing->Internet Control Message Protocol (ICMP)
Multicast->Internet Group Message Protocol (IGMP)
Tunneling -> Point to Point Tunneling Protocol (PPTP)
Tunneling-> Layer 2 Tunneling Protocol (L2TP)
Security Protocol = IPSec
Attacks =
Integrity =
port scanning (scanning tool, FIN NULL XMAS scanning, source routing exploitation, syn scanning)
session hijacking (tcp sequence number attacks, sequence attacks)
IP address spoofing,
ping scanning,
traceroute exploitation
Confidentiality =
source routing exploitation,
eavesdropping
Availability =
ICMP redirect attacks,
denial of service/distributed denial of service (syn flooding, smurf, fraggle),
ping of death,
IP fragmentation attacks (overlapping fragment attack, teardrop)
OSI Layer 4
Transport = Connection, Connectionless, 3-way handshake, Exchange of data between end systems, error free, in sequence, no losses, no duplicates, quality of service
Devices =
Protocol =
Transmission Control Protocol (TCP)
User Datagram Protocol (UDP)
SPX -> old, not answer for exam
Security Protocol =
Attacks =
Integrity =
port scanning (scanning tool, FIN NULL XMAS scanning, source routing exploitation, syn scanning)
session hijacking (tcp sequence number attacks, sequence attacks)
IP address spoofing,
ping scanning,
traceroute exploitation
Confidentiality =
source routing exploitation,
eavesdropping
Availability =
ICMP redirect attacks,
denial of service/distributed denial of service (syn flooding, smurf, fraggle),
ping of death,
IP fragmentation attacks (overlapping fragment attack, teardrop)
OSI Layer 5
Session = control of dialogues between applications, dialogue discipline, recovery, sockets/winsock
Devices =
Protocol =
Remote Procedure Call (RPC),
Real-time Transport Control Protocol (RTCP),
SOCKS (Internet socket)
Security Protocol =
Attacks = application buffer overflows
OSI Layer 6
Presentation = Data conversion. Character Code Translation. Compression. Encryption and Decryption.
Devices =
Protocol =
CODEC (Compression/Decompression)
Compression formats (Video [jpeg, h.261], Audio [mpeg, g.711]),
Abstract Syntax Notation One (ASN.1)
Security Protocol =
Attacks = application buffer overflows
OSI Layer 7
Application =
Asynchronous messaging (e-mail and news, Simple mail transfer protocol, Post office protocol, Internet message access protocol, Network news transfer protocol)
Instant messaging (Open protocols, applications and services, proprietary application and services)
Data exchange (world wide web, file transfer protocol, trivial file transfer protocol, hypertext transfer protocol, passive and active content [activex, java, javascript])
Administrative services (Simple network management protocol v3, RMON by Cisco)
Remote access services (RADIUS Remote Authentication Dial In User Service, Telnet Terminal emulation protocol, Remote login [rlogin], remote shell [rsh], remote copy [rcp])
Devices =
Protocol =
Security Protocol =
Attacks = application buffer overflows
when an adversary drains a client node’s battery by sending a constant series of management messages to the subscriber station/mobile subscriber (SS/MS)
Water torture attack
ports
FTP: 20/21
SSH: 22
Telnet: 23
SMTP: 25
DNS: 53
HTTP: 80
POP3: 110
NTP: 123
Windows File Sharing: 135, 137-139, 445
HTTPS: 443
LPR/LPD: 515
Microsoft SQL Server: 1433/1434
Oracle: 1521
H.323: 1720
PPTP: 1723
RDP: 3389
HP JetDirect printing: 9100
