LINUX installs VPN with 800 errors

The reason for the error on my side is that the iptables rule is not open on port 1723

Workaround:

chkconfig iptables offservice iptables stop

==== ==========iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADEiptables -A INPUT -i eth0 -p tcp --dport 1723 -j ACCEPTiptables -A INPUT -i eth0 -p gre -j ACCEPTiptables -A FORWARD -i ppp+ -o eth0 -j ACCEPTiptables -A FORWARD -i eth0 -o ppp+ -j ACCEPTiptables -A OUTPUT -p tcp --dport 1723 -j ACCEPTiptables -A OUTPUT -p gre -j ACCEPT=== ==========

service iptables saveservice iptables start

Try connecting to VPN again, the 800 error disappears.