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Demilitarized Zone: A neutral zone or buffer that separates the internal and external networks. The demilitarized zone (DMZ) usually exists between two firewalls. External users can access servers in the DMZ, but not the computers on the internal network. The servers in the DMZ act as an intermediary for both incoming and outgoing traffic. Also Known As: DMZ
Denial-of-Service: A denial of service (DoS) attack floods a network with an overwhelming amount of traffic, slowing its response time for legitimate traffic or grinding it to a halt completely. The more common attacks use built-in “features” of the TCP/IP protocol to create exponential amounts of network traffic. Also Known As: DoS, DDoS
DHCP: Dynamic Host Configuration Protocol (DHCP) is used to automate the assignment of IP addresses to Hosts on a network. Each machine on the network must have a unique address. Rather than manually having to enter the IP address, track which ones are in use and remember to put addresses back in the pool when devices are removed, DHCP handles all of this automatically. Each device that is configured to use DHCP will contact the DHCP server when it starts up to request an IP address. The DHCP server will assign an IP address from the range its been configured to use. The IP address has a lease duration. When the device is removed from the network, or when the lease expires, the IP address is placed back in the pool to be used by another device. Also Known As: Dynamic Host Configuration Protocol
DNS Poisoning: See Pharming Also Known As: Pharming
DNS: The Domain Name System (DNS) was created to provide a way to translate domain names to their corresponding IP addresses. It is easier for users to remember the domain name, such as yahoo.com, than to try and remember the actual IP address (for example 65.37.128.56) of each site they want to visit. The DNS server maintains a list of domain names and IP addresses so that when a request comes in it can be pointed to the correct corresponding IP address.
Keeping a single database of all domain names and IP addresses in the world would be exceptionally difficult, if not impossible. For this reason the burden has been spread around the world. Companies, web hosts and ISP’s and other entities that choose to do so maintain their own DNS servers. Spreading the workload like this speeds up the whole process and provides better security instead of relying on a single source. Also Known As: Domain Name System
Dumpster Diving: Dumpster diving is a fancy, glorified way of saying “trash picking”. Dumpster diving, or trash picking, can lead to information which could be used to compromise a network or identity. If you discard bank statements, credit card statements or other sensitive information without first shredding or otherwise destroying it, you may be at risk for an attacker to gain information about you through dumpster diving. Also Known As: Trash Picking