PPTP

安裝yum第三方EPEL套件庫

sudo yum install epel-release -y

清除快取

sudo yum clean all -y

更新套件庫

sudo yum update -y

安裝PPTP
```
sudo yum install ppp pptpd -y
```
備份設定擋
```
cp /etc/pptpd.conf /etc/pptpd.conf.bak
```
打開/etc/pptpd.conf，拉到最下面新增
```
localip 10.0.10.1
remoteip 10.0.10.2-254
```

備份設定擋

cp /etc/ppp/options.pptpd /etc/ppp/options.pptpd.bak

搜尋ms-dns，將前面#去掉如下
```
ms-dns 8.8.8.8
ms-dns 8.8.4.4
```

備份設定擋

cp /etc/sysctl.conf /etc/sysctl.conf.bak

將下面的設定貼上去

net.core.wmem_max = 12582912
net.core.rmem_max = 12582912
net.ipv4.tcp_rmem = 10240 87380 12582912
net.ipv4.tcp_wmem = 10240 87380 12582912
net.core.wmem_max = 12582912
net.core.rmem_max = 12582912
net.ipv4.tcp_rmem = 10240 87380 12582912
net.ipv4.tcp_wmem = 10240 87380 12582912
net.core.wmem_max = 12582912
net.core.rmem_max = 12582912
net.ipv4.tcp_rmem = 10240 87380 12582912
net.ipv4.tcp_wmem = 10240 87380 12582912
net.ipv4.ip_forward = 1

打開/etc/rc.d/rc.local，新增設定

iptables -t nat -A POSTROUTING -s 10.0.10.0/24 -o eth0 -j MASQUERADE

設定防火牆

firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -i eth0 -p tcp --dport 1723 -j ACCEPT
firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -p gre -j ACCEPT
firewall-cmd --permanent --direct --add-rule ipv4 filter POSTROUTING 0 -t nat -o eth0 -j MASQUERADE
firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 0 -i ppp+ -o eth0 -j ACCEPT
firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 0 -i eth0 -o ppp+ -j ACCEPT
firewall-cmd --reload