Anatoly Pashin b1rdex

Routing tips for VPNs on OS X

When VPNs Just Work™, they're a fantastic way of allowing access to a private network from remote locations. When they don't work it can be an experience in frustration. I've had situations where I can connect to a VPN from my Mac, but various networking situations cause routing conflicts. Here are a couple of cases and how I've been able to get around them.

Specific cases

Case 1: conflicting additional routes.

In this example the VPN we are connecting to has a subnet that does not conflict with our local IP, but has additional routes that conflict in some way with our local network's routing. In my example the remote subnet is 10.0.x.0/24, my local subnet is 10.0.y.0/24, and the conflicting route is 10.0.0.0/8. Without the later route, I can't access all hosts on the VPN without manually adding the route after connecting to the VPN:

Multi-Threading in PHP with pthreads

A Brief Introduction to Multi-Threading in PHP

Foreword
Execution
Sharing
Synchronization
Pitfalls

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

	<?php
	class sfWidgetFormSchemaFormatterBootstrap extends sfWidgetFormSchemaFormatter
	{
	protected
	$rowFormat = "<div class=\"control-group %row_class%\">\n %label%\n <div class=\"controls\">\n %field%\n %error%\n %help%\n %hidden_fields%\n </div>\n</div>\n",
	$errorRowFormat = '%errors%',
	$errorListFormatInARow = "<span class=\"help-inline\">%errors%</span>\n",
	$errorRowFormatInARow = "%error% ",
	$namedErrorRowFormatInARow = "%name%: %error% ",
	$helpFormat = '<p class="help-block">%help%</p>',

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	# source : http://code.google.com/p/natvpn/source/browse/trunk/stun_server_list
	# A list of available STUN server.

	stun.l.google.com:19302
	stun1.l.google.com:19302
	stun2.l.google.com:19302
	stun3.l.google.com:19302
	stun4.l.google.com:19302
	stun01.sipphone.com
	stun.ekiga.net

	select.form-control + .chosen-container.chosen-container-single .chosen-single {
	display: block;
	width: 100%;
	height: 34px;
	padding: 6px 12px;
	font-size: 14px;
	line-height: 1.428571429;
	color: #555;
	vertical-align: middle;
	background-color: #fff;

	<?php

	/**
	* Script for flushing bytecode cache
	*
	* usage:
	* php flush_cache.php unix:///var/run/php5-fpm.sock
	* php flush_cache.php 127.0.0.1 9000
	*
	* Change SECRET bellow before use!