DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.
Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.
Superscope: When we combine two or more scopes together its called super scope.
IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.
There are four layers: the Network Layer, Internet Layer, Trport Layer and Application Layer.
RAS (Remote Access Services) refers to any combination of hardware and software to enable remote access to tools or information that typically reside on a network of IT devices.
BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.
A central component of the Windows platform, Active Directory directory service provides the me to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.
A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network
The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable.
The theoritical length is 100 meters but after 80 meters you may see drop in speed due to loss of signal.
RIP (Routing Information Protocol) is used by routers to send data from one network to another.
Switches which can be administered are calledmanageable switches. For example we can create VLAN for on such switch. On no manageable swiches we can't do so.
Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.
There are 7 layers: physical layer, data link layer, network layer, trport layer, session layer, presentation layer, and application layer.
VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB:
Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.
Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.
PST file is used to store the mails locally when using outlook 2000 or 20@OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.
Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.
Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.
There are two types of LAN cables used – ‘Cat 5’ and ‘Cat 6.’ Cat 5 can support 100Mbps of speed while Cat 6 can support 1Gbps of speed.
RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS. Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.
Domain is created when we install Active Directory. It's a security boundary which is used to manage computers inside the boundary. Domain can be used to centrally administor computers and we can govern them using common policies called group policies.
We can't do the same with workgroup.
DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.
Forward lookup: Converting names to IP address is called forward lookup.
Reverse lookup: Resolving IP address to names is called reverse lookup.
'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.
'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.
A router is a layer 3 network device used to establish communication between different networks.
The roles of a router are –
When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X.
APIPA stands for Automatic private IP addressing. Its in the range of 169.254.X.X.
Install another system. Insall the OS with the lates pathces, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.