Install pptp VPN on centOS

Install VPN PPTP Server on CentOS 6

by SECAGUY on 28 OCTOBER 2011 · 103 COMMENTS

At this moment, my designer encounter problem to access target.com, an online shopping website to see some of the stuff for their design work. Target.com only allowed connections from USA and Canada at this moment due to their website crash issue last couple of weeks. Since this is quite urgent, I need to setup a VPN server so they can use it as a jump point to access websites in USA and Canada. I will use my MySQL server to serve as VPN server as well.

In this tutorial, I will use pptp as protocol to connect to VPN server using a username and password, with 128 bit MPPE encryption. Variable as below:

OS: CentOS 6 64bit
VPN server:  209.85.227.26
VPN client IP: 209.85.227.27 - 209.85.227.30
VPN username: vpnuser
Password: myVPN$99

1. Install ppp via yum:

$ yum install ppp -y

2. Download and install pptpd (the daemon for point-to-point tunneling). You can find the correct package at this website http://poptop.sourceforge.net/yum/stable/packages/ :

$ cd /usr/local/src $ wget http://poptop.sourceforge.net/yum/stable/packages/pptpd-1.3.4-2.el6.x86_64.rpm $ rpm -Uhv pptpd-1.3.4-2.el6.x86_64.rpm

3. Once installed, open /etc/pptpd.conf using text editor and add following line:

localip 209.85.227.26 remoteip 209.85.227.27-30

4. Open /etc/ppp/options.pptpd and add  authenticate method, encryption and DNS resolver value:

require-mschap-v2 require-mppe-128 ms-dns 8.8.8.8

5. Lets create user to access the VPN server. Open /etc/ppp/chap-secrets and add the user as below:

vpnuser pptpd myVPN$99 *

The format is: [username] [space] [server] [space] [password] [space][IP addresses]

6. We need to allow IP packet forwarding for this server. Open /etc/sysctl.conf via text editor and change line below:

net.ipv4.ip_forward = 1

7. Run following command to take effect on the changes:

$ sysctl -p

8. Allow IP masquerading in IPtables by executing following line:

$ iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE $ service iptables save $ service iptables restart

Update: Once you have done with step 8, check the rules at /etc/sysconfig/iptables. Make sure that the POSTROUTING rules is above any REJECT rules.

9. Turn on the pptpd service at startup and reboot the server:

$ chkconfig pptpd on $ init 6

Once the server is online after reboot, you should now able to access the PPTP server from the VPN client. You can monitor /var/log/messages for ppp and pptpd related log. Cheers!

How to solve PPTP VPN client cannot open web pages

If you are running PPTP VPN server (pptpd) on a Linux host, and your PPTP clients cannot open any web pages, here is a checklist for you to debug the problem:

1. Is there another client connected to the PPTP VPN server?
   If two clients are under the same NAT, they may not connect to the same PPTP VPN server at once. This is a limitation in PPTP implementation.
2. Does PPTP VPN server allow IP forwarding?Check kernel configuration on the PPTP server and make sure that ip_forward is enabled by running:
   # sysctl -a | grep ip_forwardIf you see net.ipv4.ip_forward = 0That means IP forwarding is not enabled and you must enable it. One way is to edit /etc/sysctl.conf and change/add the following line:net.ipv4.ip_forward = 1
3. Does PPTP VPN server firewall masquerade network interfaces?
   It is essential to configure firewall to masquerade public Internet network interface and ppp network interface, here are the firewall rules:
   iptables -A POSTROUTING -t nat -o eth0 -j MASQUERADE
   iptables -A POSTROUTING -t nat -o ppp+ -j MASQUERADE
4. Does PPTP VPN server have clamp-mss-to-pmtu set in iptables?If your VPN clients can visit certain websites but not others, then you are very likely encountering MTU problem. It can be fixed easily by the following iptables rule:
   iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
5. Are DNS server addresses set correctly on PPTPD configuration?If your VPN clients can ping IP addresses (such as Google DNS 8.8.8.8) but not visiting any websites, then it is likely a DNS issue. You can set DNS server addresses on VPN clients, or set them on the VPN server's options.pptpd, change/add the following lines:
   ms-dns 8.8.8.8
   ms-dns 8.8.4.4

install gearman CentOS with php extension

You have to have install remi repo for yum ... for install it ... try google (very fast)
yum install gearmand
yum install libgearman

yum -y install --enablerepo=remi php-pecl-gearman

Reset MySQL password

Recover MySQL root Password

by NIX CRAFT on APRIL 18, 2006 · 265 COMMENTS· LAST UPDATED AUGUST 4, 2010

in DEBIAN LINUX, LINUX, MYSQL

You can recover MySQL database server password with following five easy steps.

Step # 1: Stop the MySQL server process.

Step # 2: Start the MySQL (mysqld) server/daemon process with the --skip-grant-tables option so that it will not prompt for password.

Step # 3: Connect to mysql server as the root user.

Step # 4: Setup new mysql root account password i.e. reset mysql password.

Step # 5: Exit and restart the MySQL server.

Here are commands you need to type for each step (login as the root user):

Step # 1 : Stop mysql service

# /etc/init.d/mysql stop
Output:

Stopping MySQL database server: mysqld.

Step # 2: Start to MySQL server w/o password:

# mysqld_safe --skip-grant-tables &
Output:

[1] 5988
Starting mysqld daemon with databases from /var/lib/mysql
mysqld_safe[6025]: started

Step # 3: Connect to mysql server using mysql client:

# mysql -u root
Output:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Step # 4: Setup new MySQL root user password

mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

Step # 5: Stop MySQL Server:

# /etc/init.d/mysql stop
Output:

Stopping MySQL database server: mysqld
STOPPING server from pid file /var/run/mysqld/mysqld.pid
mysqld_safe[6186]: ended
[1]+  Done                    mysqld_safe --skip-grant-tables

Step # 6: Start MySQL server and test it

# /etc/init.d/mysql start
# mysql -u root -p