Christian Kuhtz ckuhtz

Workarounds for Netflix and the blocking of Hurricane Electric IPv6 tunnels

The dreaded "You seem to be using an unblocker or proxy." error message. Cool story bro.

This gist was essentially created out of my own rant about Netflix being hostile to IPv6 tunnel services since June 2016. You are welcome to read my opinion on the matter, this is the more technical side to the issue and how to combat it within your own network.

Since I wrote this, various GitHub users have contributed their thoughts and ideas which has been incorporated into this gist. Thank you to everyone who have contributed their own methods and implementations.

The problem

Netflix now treats IPv6 tunnel brokers (such as Hurricane Electric) as proxy servers. A while ago it became apparent to users and Netflix that somewhat by accident, IPv6 tunnel users were being served content outside of their geolocation because of the way Netflix was identifyi

GCC compiler optimization for ARM-based systems

2017-03-03 fm4dd

The gcc compiler can optimize code by taking advantage of CPU specific features. Especially for ARM CPU's, this can have impact on application performance. ARM CPU's, even under the same architecture, could be implemented with different versions of floating point units (FPU). Utilizing full FPU potential improves performance of heavier operating systems such as full Linux distributions.

-mcpu, -march: Defining the CPU type and architecture

These flags can both be used to set the CPU type. Setting one or the other is sufficient.

Emulate Raspberry pi on windows

Following files required to emulate raspberry pi on windows

QEMU Emulator
Raspberry pi kernel
Raspberry pi OS image

QEMU emulator

QEMU is an emulator

If you run VMware Workstation 11 or above you may encounter high CPU usage from process khugepaged on Ubuntu 15.04+

The fix is to disable transparent hugepages. It seems Ubuntu has it enabled by default.

You can check the current status on your system by running:

cat /sys/kernel/mm/transparent_hugepage/enabled

cat /sys/kernel/mm/transparent_hugepage/defrag

Emulating a Raspberry Pi with QEMU

Goal: Emulate a Raspberry Pi with QEMU in order to run the Raspbian O/S (based on Debian Linux).

The current setup is not ideal. For one thing, the maximum RAM allowed using the "versatile-pb" firmware is 256 Mb. In addition, only the most basic peripherals, a keyboard and mouse, are supported.

A number of articles have been written on this topic. Most are outdated, and the few recent ones are missing key information.

Simple Hexdump

A simple hexdump module for Python.

Installation

The preferred installation method is:

pip install simple-hexdump

NB

This is just my own notes for me trying the same thing in the future (and probably make the exact same mistake as I did today!), so please do not rely on this too much ...
This is a fork of a gist by plembo. Check out there for original instructions. Sorry, but I think not much changes have been made, meaning probably you might not have any particular reason to prefer this gist over the original one :(
I tried this on my Alter Linux platform, so I believe most of the notes here would apply to any Arch-based distros (not sure though).

Emulating a Raspberry Pi with QEMU

Goal: Emulate a Raspberry Pi with QEMU in order to run the Raspbian O/S (based on Debian Linux).

The current setup is not ideal. For one thing, the maximum RAM allowed using the "versatile-pb" firmware is

	# this assumes WAN is eth0 and LAN is switch0. Please adjust for your own setup

	configure

	# Tunnel first
	edit interfaces tunnel tun0
	set encapsulation sit
	set local-ip xxx.xxx.xxx.xxx # your WAN IP
	set remote-ip xxx.xxx.xxx.xxx # HE.net Server IPv4 Address
	set address xxxx:xxxx:xxxx:xxxx::2/64 # Client IPv6 Address

	pct create <id> /var/lib/vz/template/cache/centos-7-default_20170504_amd64.tar.xz \
	-arch amd64 \
	-ostype <centos\|ubuntu\|etc> \
	-hostname <hostname> \
	-cores <cores> \
	-memory <memory(MB)> \
	-swap <swap(MB)> \
	-storage local-lvm \
	-password \
	-net0 name=eth0,bridge=<bridge>,gw=<gateway>,ip=<cidr>,type=veth &&\

	## this is a quick and dirty script to remotely login to a Netgear CM1000 modem,
	# grab the docsis logs and format them as a csv for saving later. the webpage will only show so many
	# and logs can be eventually be lost. this is also an easier way to grab/view them
	# last tested on Firmware Version V7.01.01 jan 2 2022
	import requests
	import re
	from time import time
	from csv import DictWriter
	from xml.dom.minidom import parseString
	from datetime import datetime