Operating System Fundamentals and Network Addressing Concepts
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Operating System Fundamentals
Kernel and Core Components
1. The memory resident part of an operating system is called the kernel. The kernel manages hardware resources and enforces access control. The parts are loaded when the system starts up and stay running as long as the system is on.
2. API stands for Application Programming Interface, which allows different applications to communicate and work together.
3. Device Drivers control communication between devices and operating systems, such as network adapters and graphic cards. Device drivers also provide a layer that allows the operating system to send commands to hardware devices.
4. A process is an execution instance of a program. A process executes instructions in memory, while a program has instructions stored in a file and operates on its own.
File System Descriptions
5. Physical description shows how a file's data is stored on storage media and how it is displayed and retrieved from a program. Logical description is how operating systems and applications interact with a file's content and methods.
Concurrency Concepts
- Multiprogramming runs multiple programs at the same time on a single processor system that switches between programs, similar to parallel execution.
- Multiuser systems allow multiple users to use the same computer system simultaneously while having their own accounts. The operating system manages access permissions, resources, and ensures that accounts do not interfere with each other.
- Multiprocessing involves systems with multiple processors that can carry out tasks in parallel, allowing concurrent execution of processes and handling tasks more efficiently than single-processor systems.
Network Addressing and TCP/IP
IP Addressing and Subnetting
1. An IP address mask is used to separate the different parts of an address. When masks are combined with an IP address using Boolean algebra, individual components of the address can be identified.
Example Calculations
- For the IP address
200.60.40.88/24: The network address would be200.60.40.0and the host address would be0.0.0.88. There can be 254 hosts. - For the IP address
222.66.44.80/26, the network address would be222.66.44.64and the host address as0.0.0.80, having 62 hosts available.
DHCP and ARP Protocols
2. DHCP lease occurs when a client locates the DHCP server. In order to obtain configuration, the DHCP server responds with a lease that provides the IP address and parameters such as the network's domain name, the IP address of the local DNS server, the subnet mask to identify other nodes, and the default IP address of the Internet gateway.
3. The ARP (Address Resolution Protocol) is used to map hardware addresses to IP addresses. When a host sends a packet to another host, the IP address sends out an ARP packet that checks if the MAC address corresponds to the IP address.
TCP/IP Layer Relationships
4. The relationships between layers in the TCP/IP model involve corresponding layers at the source and destination. This ensures data is encapsulated and delivered so that the protocol stack is maintained and has integrity.