ISC2 - Study Notes 8 Flashcards
supports many additional security features. These include authentication, access control with mechanisms such as permissions, encryption for confidentiality, hashing for integrity, and the use of digital signatures for nonrepudiation.
The Application Layer
Ethernet networks support Carrier Sense Multiple Access/Collision Detection (CSMA/CD).
In Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA), systems listen before transmitting data. If they sense that other systems are transmitting data, they wait a random amount of time to check again before sending traffic. Wireless networks such as 802.11 networks use CSMA/CA.
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also support Request To Send (RTS) and Clear To Send (CTS) to negotiate traffic. When a computer wants to transmit data, it sends out the RTS signal. The destination replies with a CTS signal and waits for the transmission.
Wireless Networks
When an electrical signal travels down a wire, it will reflect back when it reaches the end unless the wire has a terminator. This reflected signal corrupts other data transmissions on the bus. The terminator is a connector that prevents this signal reflection. Removing the terminator effectively takes the entire bus network down.
Bus Topology
is a combination of a bus topology and a star topology. Instead of connecting multiple computer nodes in the bus configuration, it connects multiple star networks along a type of a bus network. Because all of the star networks are connected to each other via the bus network, a break in the bus network disconnects the star networks from each other. However, a break in the bus does not affect communication within any of the individual star networks.
Tree Topology
each device is connected together in a ring. Additionally, the ring includes a logical token that controls when computers can communicate. This prevents collisions because computers can send traffic on the network only when they have the token. If the ring breaks no other computers are able to communicate. With MSAU a single failure doesnt take down the entire network. By adding more and more computers will significantly reduce performance.
Token Ring Network
It uses fiber-optic connections instead of copper connections and thus supports much higher bandwidth. It also uses dual rings. The second ring is used only when the system detects an error in the primary ring.
Fiber Distributed Data Interface (FDDI)
mesh topology with the formula n(n – 1)/2
peer-to-peer network, systems are independent of each other and authentication is decentralized.
client-server network, a server holds accounts and provides centralized authentication.
IPv4 address uses 32 bits.
IPv6 address uses 128 bits.
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ARP resolves IP addresses to physical or hardware addresses (MAC addresses). RARP allows a client with a MAC address to get an IP address. BootP allows a diskless client with a MAC address to get an IP address and retrieve a bootable operating system image.
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uses the Network Discovery Protocol (NDP) instead of ARP to resolve IPv6 addresses to the IPv6 version of MAC addresses. IPv6 also does : Automatically configures nodes, Discovers other nodes on the network, Locates available routers on the network, Detects duplicate addresses on the network.
IPv6
