How to SSH to a VirtualBox guest externally through a host?

Network in NAT

port forward
Host port 2222, guest port 22, name ssh, other left blank

VirtualBox Static ip

Virtualbox network in BridgeMode

sudo vi /etc/network/interfaces

auto eth0
iface eth0 inet static
   address 192.168.Y.X
   netmask 255.255.255.0
   network 192.168.Y.0
   gateway 192.168.Y.1

sudo service networking restart

Whats is the best way to generate uuidv4 in php?

Whats is the best way to generate uuidv4 in php?
Some people use this: https://github.com/ramsey/uuid
Others can user a system call like file_get_contents('/proc/sys/kernel/random/uuid');
And others just a simple function.

What's the best way? Depending on your needs, of course.
I can use all the option, so I decide to make a benchmark, and I was surprised...

<?php
require __DIR__.'/../vendor/autoload.php';
function gen_uuidv4(){
    return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
            // 32 bits for "time_low"
            mt_rand(0,0xffff),mt_rand(0,0xffff),
            // 16 bits for "time_mid"
            mt_rand(0,0xffff),
            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 4
            mt_rand(0,0x0fff)|0x4000,
            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            mt_rand(0,0x3fff)|0x8000,
            // 48 bits for "node"
            mt_rand(0,0xffff),mt_rand(0,0xffff),mt_rand(0,0xffff));
}
// #####################################
$i=microtime(true);
for($a=0;$a<1000000;$a++){
    file_get_contents('/proc/sys/kernel/random/uuid');
}
$f=microtime(true);
$t1=$f-$i;
echo $t1;
echo '<br>';
// #####################################
$i=microtime(true);
for($a=0;$a<1000000;$a++){
    gen_uuidv4(true);
}
$f=microtime(true);
$t2=$f-$i;
echo $t2;
echo '<br>';
// #####################################
$i=microtime(true);
for($a=0;$a<1000000;$a++){
    \Ramsey\Uuid\Uuid::uuid4();
}
$f=microtime(true);
$t3=$f-$i;
echo $t3;


T1: 10.762820005417(s) System Call in Ubuntu 14.04
T2: 6.3450520038605(s) simple function
T3: 30.962769985199(s) blotted library

Choose wisely :)