Notes, summaries, assignments, exams, and problems for Computers

Basic Protocol Filters

Use these filters to quickly isolate traffic based on common protocols:

• arp (Address Resolution Protocol)
• dns (Domain Name System)
• http (Hypertext Transfer Protocol)
• https (HTTP Secure)
• icmp (Internet Control Message Protocol)
• ip (Internet Protocol)
• ipv6 (Internet Protocol Version 6)
• ntp (Network Time Protocol)
• smtp (Simple Mail Transfer Protocol)
• ftp (File Transfer Protocol)
• ssh (Secure Shell)
• tls (Transport Layer Security)
• udp (User Datagram Protocol)
• tcp (Transmission Control Protocol)
• dhcp (Dynamic Host Configuration Protocol)
• bootp (Bootstrap Protocol)
• radius (Remote Authentication Dial-In User Service)
• snmp (Simple Network Management Protocol)
• kerberos
• smb (Server Message Block)
• nbns (NetBIOS Name Service)
• nbss (NetBIOS Session Service)

Assembly Language Code Analysis and Solutions

Section 1: Instruction Correctness Check

.data

calculate WORD 100
wVal DWORD 2

Instructions:

1. mov bl, calculate
2. mov ax, wVal

Question 1: Are the above two instructions correct? If not, justify your claim. [2 marks]

Answer:

Both instructions are incorrect.

• For the mov operation, the operands must generally be of the same size.
• In instruction 1, bl is 8 bits (1 byte), but calculate is defined as a WORD (16 bits or 2 bytes). The operand sizes do not match.
• In instruction 2, ax is 16 bits (2 bytes), but wVal is defined as a DWORD (32 bits or 4 bytes). The operand sizes do not match.

Section 2: Loop Pseudo-code

Question 2: Write the pseudo-code for the loop that calculates the sum of the integers 3 + 2 + 1. [2 marks]

P1: Python String Manipulation Techniques

Demonstrating String Operations

s = "hello"
print(s.capitalize())
print(s.upper())
print(s.rjust(100))
print(s.center(100))
print(s.replace('l','(M)'))
print(s)
print("don't")

Indexing

a = 'symbiosis2024'
print(a[2])

Negative Indexing

print(a[-1])
print(a[-6])

Slicing

print(a[9:12])
print(a[9:])
print(a[9:-1])
print(a[:8])
print(a[-12:-1])

Stride [start index:end index:step size]

print(a[0:13:2])
print(a[0::2])

Concatenation

b = 'hello'
c = 'world'
d = b + c
print(d)
e = b + " " + c
print(e)

Repetition

f = a * 3
print(f)
g = "2024"
print(g * 2)
print(a + '2')

Reversing a String

print(a[::-1])

Split

h = "sspu"
print(h.split()) # Returns a list
i = "05/08/2024"
print(i.split("/"))
j = "14:20:25"
print(j.split("

Nmap Options

-PE: Quickly check if host is up.

-sn: Disable port scanning (host discovery).

-n: Disables DNS resolution (checks IP online without looking up hostnames).

-O: OS detection.

-A: OS detection, Version detection, Script scanning, traceroute.

-sV: Service detection (banner info, version).

-vV: Provides verbose output.

-sC: Scan with default scripts for additional info gathering.

--min-rate=5000: Ensures scan sends at least 5k packets per second.

nmap --script smb-enum-shares.nse -p 445 (ip): List shares and their properties.

To see scripts starting with X: ls /path/X

To execute script with script tracing: sudo nmap -script=smb-os-discovery -script-trace target_ip

To enumerate the SMB share files: sudo nmap -script=smb-enum-shares target_ip

Vulnerability... Continue reading "Nmap, Netcat, and Metasploit Commands Cheat Sheet" »

🧾 Data Transfer Instructions

These instructions are used to move data between registers, memory, and I/O ports.

➕ Arithmetic Instructions

These instructions perform basic mathematical operations.

Steps for Training a Machine Learning Project in the Cloud

Definition: Cloud ML Project Training

Training an ML Project in the Cloud means utilizing cloud-based resources and services to build, train, and optimize a Machine Learning model.

The Seven Key Steps in Cloud ML Training

1. Data Collection: Gather and upload the dataset to cloud storage.
2. Data Preprocessing: Clean and prepare data using cloud notebooks or specialized processing services.
3. Model Selection: Choose the appropriate algorithm or utilize a pre-built model architecture.
4. Training: Use scalable cloud compute resources (GPUs/TPUs) for intensive model training.
5. Evaluation: Test model accuracy and performance using validation data.
6. Hyperparameter Tuning: Optimize model parameters for better

Circular Queue Implementation Using Linked Lists

This C program demonstrates the implementation of a circular queue using a linked list structure. The queue handles integer data.

Data Structure Definition

#include <stdio.h>
#include <stdlib.h>

typedef struct QueueType {
    int Data;
    struct QueueType *Next;
} QUEUE;

QUEUE *Front = NULL; // Pointer to the front of the queue
QUEUE *Rear = NULL;  // Pointer to the rear of the queue

// Function prototypes
void Enqueue(int Num);
int Dequeue();
void DisplayQueue();
int Menu();

Enqueue Operation

The Enqueue function inserts a number into the circular queue. It handles memory allocation and maintains the circular link by ensuring Rear->Next always points to Front.

void Enqueue(int Num)

This document presents Java code snippets demonstrating two distinct functionalities: user name generation and management, and a car repair scheduling system. Each section includes method implementations with explanations of their purpose and logic.

User Name Management System

The UserName class is designed to generate and manage potential user names based on a user's first and last names. It also provides functionality to filter out names that are already in use.

UserName Class Constructor

This constructor initializes a UserName object, populating a list of possible user names. It assumes that firstName and lastName are valid strings containing only letters and have a length greater than zero.

import java.util.ArrayList;

public class UserName {