Pradyumna Joshi PSJoshi

Real-world networking datasets

Please comment below if you have an update, e.g., with another networking-related dataset.

Dataset repos or tools

Finding datasets: New Google Dataset search
Mendeley Data: https://data.mendeley.com/datasets
Kaggle Data: https://www.kaggle.com/datasets
Google's M-Lab networking performance data sets: https://www.measurementlab.net/data/

Converting Nmap xml reports to html

Nmap is popular network scanner for scanning of ports and vulnerabilities and supports various output formats like XML. As a result, scan data can be parsed by other tools such as Metasploit or ZenMap GUI. For human readability, nmap scan output can be formatted to a nice HTML report using tool like xsltproc.

Typical Nmap scan command looks like

# nmap -sTV -p- -A -T4 -vvvv -oA

Systemctl commands

List services

# systemctl list-units --type=service

Show running services

# systemctl list-units --type=service --state=running

List all services

Explanation for different repositories for Raspberry Pi

File:/etc/apt/sources.list
deb http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
deb http://archive.raspberrypi.org/debian/ bullseye main

deb http://deb.debian.org/debian bullseye main contrib non-free
deb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb http://deb.debian.org/debian bullseye-updates main contrib non-free

Setting watchdog timer in Raspberry Pi

Check WDT module is enabled in kernel In recent raspberry pi boards, the module for watchdog is bcm2835_wdt and it comes precompiled into kernel directly. So it doesn’t have to be enabled manually anymore and also it will not show when running lsmod.

To check if you have this module precompiled in kernel, you can run:

pi@raspberrypi:~ $ sudo cat /lib/modules/$(uname -r)/modules.builtin | grep wdt
kernel/drivers/watchdog/bcm2835_wdt.ko
pi@raspberrypi:~ $ sudo cat /var/log/kern.log* | grep watchdog
Oct 31 12:17:02 raspberrypi kernel: bcm2835-wdt bcm2835-wdt: Broadcom BCM2835 watchdog timer

Install smart card driver - PC/SC (Windows/Linux smart card base components)

# apt-get update
# apt-get install pcscd

# check if smart card is detected
# lsusb

# apt install pcsc-tools
# pcsc_scan

Read SD memory card information

$ sudo udevadm info -a -n /dev/sdb

SD card vendors should be in /sys/class/mmc_host within /sys/class

Try searching /sys for some MMC (SD) specific keywords for ARM-based embedded system

$ find /sys -name "oemid"

Generate self signed certificate

Self-signed certificates are convenient when developing locally. Of course, these are not be used in production environments. If you are running a public site, it's recommended to use any commercial certificate recognized by Browser. "Let's Encrypt" has revolutionalized the certificate eco-system and you can easily use/deploy them on public facing websites.

For experimentation and testing, self-signed certificates is the easiest approach. Steps to get self-signed certificate are given below:

Install openssl

# apt-get install openssl

Clear RAM-cache and Swap in Linux

It is possible to clear cache without interrupting any process or service. sync will flush the file system buffer and drop_cache will clean cache without killing any application/service.

Clear PageCache only

# sync; echo 1 > /proc/sys/vm/drop_caches

	### Cron job using bash script
	```
	#!/bin/sh
	crontab -l > cron_backup
	echo "0 10 * * * sudo /home/<user>/job.sh >/dev/null 2>&1" >> cron_backup
	crontab cron_backup
	rm cron_backup
	```
	Another version
	```