Linux firewall ufw settings for local PC

sudo ufw enable

sudo ufw default deny incoming

sudo ufw allow from 192.168.1.0/24 to any port *****

sudo ufw allow from 192.168.1.0/24 to any port ***** proto udp

sudo ufw allow from 192.168.1.0/24 to any port ****

sudo ufw allow from 192.168.1.0/24 to any port 22

sudo ufw allow from 192.168.1.0/24 to any port 3389

sudo ufw allow from 192.168.1.0/24 to any port 445 proto tcp

sudo ufw status verbose

ss -tulpn

upnpc -l

curl ifconfig.me // compare with PC public ISP IP

nmap -p **,****,***** IP-address (check PC and ISP)

ip a

ip -4 addr

ip -6 addr // global address (not fe80::)

nmap -6 -p ****,***** YOUR_IPV6

Synchronize Android and Kubuntu folders

Install dk.tacit.android.foldersync.lite

https://www.apkmirror.com/apk/tacit-dynamics/foldersync/foldersync-2-9-16-release/foldersync-2-9-16-android-apk-download/

Create account for SMB server in FolderSync.

Create new sync and choose interval.

That's easiest way to sync files between Android devices and Linux PC.

Delete useless user: sudo deluser --remove-all-files <username>

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sudo apt install openssh-server

systemctl status ssh

hostname -I

ifconfig

ip a

sudo adduser ftpdrop

[sudo] password for user:

info: Adding user `ftpdrop' ...

Is the information correct? [Y/n] y

info: Adding new user `ftpdrop' to supplemental / extra groups `users' ...

info: Adding user `ftpdrop' to group `users' ...

id ftpdrop

groups ftpdrop

getent group users // show users in group

sudo deluser ftpdrop users // remove user from group

ssh-keygen -t ed25519 -f ~/ftpdrop_key

Generating public/private ed25519 key pair.

sudo mkdir /home/ftpdrop/.ssh

sudo nano /home/ftpdrop/.ssh/authorized_keys

Paste contents of /home/user/ftpdrop_key.pub

sudo chown -R ftpdrop:ftpdrop /home/ftpdrop/.ssh

sudo chmod 700 /home/ftpdrop/.ssh

sudo chmod 600 /home/ftpdrop/.ssh/authorized_keys

sudo systemctl restart ssh

"Algrotirhm Parameters EC implementation not found" on phone

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Open http://192.168.1.10:8080/videomgr.html#/modet in Firefox

F12 → Console

Add Set to remove duplicates:

[...new Set(

  [...document.querySelectorAll("a[href*='/v/modet/']")].map(a => a.href)

)].join("\n")

Explanation:

querySelectorAll → all <a>

map(a => a.href) → array of hrefs

new Set(...) → keeps only unique values

[...new Set(...)] → back to array for join("\n")

Copy output → save as list.txt

mkdir ipcam10

nano list.txt → Ctrl + Shift + V

mv list.txt ipcam10

wget -i list.txt --base=http://192.168.1.10:8080/v/modet/

Sound problems, audio glitches on Kubuntu

cmus playing music. Audio glitches when turning on monitor after sleep. analog-stereo.

Firefox playing Youtube. Monitor speakers - hdmi-stereo. Sound glitches.

journalctl --user -f | grep -i pipewire // shows nothing

pw-top // to see the current quantum and latency in real-time.

Rust Build completed with 4 failures in Android Studio

Install:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Reload environme:

source ~/.cargo/env

Verify:

which rustc

/home/user/.cargo/bin/rustc

rustc --version

rustc 1.92.0 (ded5c06cf 2025-12-08)

cargo --version

cargo 1.92.0 (344c4567c 2025-10-21)

FAILURE: Build completed with 4 failures.

1: Task failed with an exception.

-----------

* What went wrong:

Execution failed for task ':file_operations:cargoBuildArm'.

> A problem occurred starting process 'command 'rustc''

* Try:

> Run with --info or --debug option to get more log output.

> Run with --scan to get full insights.

> Get more help at https://help.gradle.org.

* Exception is:

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':file_operations:cargoBuildArm'.

at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:130)

at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:282)...

NDK is not installed in Android Studio on Linux

ls /home/user/Android/Sdk/ndk/

29.0.14206865

IF NONE > Android Studio > Tools > SDK Manager > Language & Frameworks> Android SDK > SDK Tools > Tick NDK (Side by side), tick CMake > Apply > OK

nano Project/gradle/libs.versions.toml

[versions]

compileSdk = "34"

minSdk = "21"

targetSdk = "35"

kotlin = "1.9.25"

ndk = "29.0.14206865" #r28c // ENTER VERSION OF YOUR NDK

Ctrl + Shift + O // Sync Project with Grade Files...