FAQ for VPN

Because it allows you to connect to the N.T.U.A. network from wherever you are. When connected to vpn.ntua.gr you can have access to the N.T.U.A. library, send e-mails without any alterations in your PC or have access to your local laboratory or subnetwork. In the case that you are away on a trip or you connect via a different ISP than your houses, you may use vpn.ntua.gr in order to access these services.

From anywhere you have access to the internet. The connection with N.T.U.A. takes place via a virtual connection.

There is no cost when you use the service from N.T.U.A. Nevertheless you will have to have access to the internet, probably from a telephone company. The cost of the internet connection has no correlation to the VPN service of N.T.U.A.

No! There are no time limitations or volume limitations in vpn.ntua.gr.

No! Like any other service provided by N.T.U.A. this account is strictly private and sharing it endangers your security. In the case of use by a third party, the Network Center has the right to deny you access for any time period.

Yes! For your convenience you are allowed to use this protocol.

Confirm that the application is properly installed, that no security application (firewall) interrupts the communication and that you have the latest edition of the program offered by the Network Center.  If you are trying using udp, try again using tcp. If you still cannot connect, e-mail us or call our technical support office at 210-772-1861.

The same ones that you use for all the services, like dialup, my.ntua.gr, ntua-wifi etc.

A cause for this problem is often the existence of a safety application like firewall programs which don’t allow any data transfer over the network equipment Tap. You will have to create access via the program to the openvpn as well as the network equipment Tap. If you are using Windows, check whether the DHCP Client service of Windows is activated.

Always use udp since it clearly has a better performance. If you discover that you can’t connect to udp, then try to use tcp.

This message might be due to a series of problems. Most common being:
1. Attempt to execute multiple openvpn simultaneously. For example, you are connected with udp protocol and you are trying to reconnect with tcp.
2. The ο tap-win32 adapter has been disabled. This network equipment is necessary to be on in order for the service to work. You may activate it, in case you have deactivated it, from the network connections on the control panel. If it is not there, then the network equipment is not installed, so you will have to install it. The installment offered by the network center preselects this network equipment.
3. In the case of Μιcrosoft Windows as well as in other operative systems you will need administrative rights in order to have access in this network equipment.

The editions of Windows 95, Windows 98 και Windows Me are no longer supported by their software developing company. They also don’t support the VPN application. We would recommend to upgrade your software soon.

Your browser doesn’t need any special setting. You just need to download and execute the VPN application offered from the Network Center every time you want to connect via a private network to N.T.U.A.

If in the past you were using openvpn from another organization, probably the openvpn-gui setting are wrong. You may try to apply the following file: openvpn-gui-default-settings.reg

Your time and date setting on your computer is probably wrong. Please correct it and retry.

It is possible that you are using an older edition of the tunnelblick software. Since January the 4^th 2013 the available software on the Network Centre’s page is based on tunnelblick 3.3beta20 which fixes this problem.