cwbsw

If you're using a high-end bluetooth headset on your Macbook Pro it's likely your mac is using an audio codec which favors battery efficiency over high quality. This results in a drastic degradation of sound, the SBC codec is the likely culprit, read more about it here.

Find out what codec you're using

Play a song on your headphones
Option (⌥) click the Bluetooth button at the top of your screen
If you're using AAC or aptX, you can stop here—those are the highest quality codecs.

Change your codec to AAC or aptX

朴素VPN：一个纯内核级静态隧道

由于路由管控系统的建立，实时动态黑洞路由已成为最有效的封锁手段，TCP连接重置和DNS污染成为次要手段，利用漏洞的穿墙方法已不再具有普遍意义。对此应对方法是多样化协议的VPN来抵抗识别。这里介绍一种太简单、有时很朴素的“穷人VPN”。

朴素VPN只需要一次内核配置（Linux内核），即可永久稳定运行，不需要任何用户态守护进程。所有流量转换和加密全部由内核完成，原生性能，开销几乎没有。静态配置，避免动态握手和参数协商产生指纹特征导致被识别。并且支持NAT，移动的内网用户可以使用此方法。支持广泛，基于L2TPv3标准，Linux内核3.2+都有支持，其他操作系统原则上也能支持。但有两个局限：需要root权限；一个隧道只支持一个用户。

朴素VPN利用UDP封装的静态L2TP隧道实现VPN，内核XFRM实现静态IPsec。实际上IP-in-IP隧道即可实现VPN，但是这种协议无法穿越NAT，因此必须利用UDP封装。内核3.18将支持Foo-over-UDP，在UDP里面直接封装IP，与静态的L2TP-over-UDP很类似。

创建一个朴素VPN

OS X Preferences

most of these require logout/restart to take effect

# Enable character repeat on keydown
defaults write -g ApplePressAndHoldEnabled -bool false

# Set a shorter Delay until key repeat

	#!/usr/bin/env bash

	# Builds mpv & mpv.app on Apple silicon Macs.
	# Run this script from the root directory of the mpv repo.

	# if anything fails, gtfo
	set -ex

	meson setup build
	meson compile -C build

	#!/bin/zsh
	# standalone script to build qBittorent for macOS (including Apple Silicon based Macs)
	#
	# only Xcode must be installed (Xcode 12 is required to produce arm64 binaries)
	# all required dependencies and tools are automatically downloaded and used only from script's working directory
	# (can be specified), nothing is installed into the system
	# working directory is removed on completion if it was not specified
	#
	# by default script produces binaries for the architecture it was launched on, but cross-compilation is also supported
	# in both directions, i.e. x86_64 -> arm64 and arm64 -> x86_64

	From 966471712184cfb3b067f2ae8dad9d8e2a896cae Mon Sep 17 00:00:00 2001
	From: Bearice Ren <[email protected]>
	Date: Tue, 20 Sep 2016 11:52:08 +0800
	Subject: [PATCH] add filter-aaaa option

	---
	src/dnsmasq.h \| 3 ++-
	src/option.c \| 3 +++
	src/rfc1035.c \| 9 +++++++++
	3 files changed, 14 insertions(+), 1 deletion(-)

	#!/bin/bash

	if [ "$4" == "" ]; then
	echo "usage: $0 <local_ip> <remote_ip> <new_local_ip> <new_remote_ip>"
	echo "creates an ipsec tunnel between two machines"
	exit 1
	fi

	SRC="$1"; shift
	DST="$1"; shift

	#!/bin/bash

	# Setup encrypted IPv4 tunnel over IPv4 or IPv6 on two Linux nodes using SSH for tunnel setup.
	# Requires only ipsec-tools, iproute2, ssh and necessry kernel modules locally and remotely.

	# Warning: it flushes IPsec settings both locally and remotely.
	# Don't use with other IPsec tunnnels.

	# Sample usage:
	# simplevpn -6 fc::1 fc::2 ssh -T root@fc::2