Computer and Internet
Firewall and VPN

The firewall is set up to secure all data and machines in IIS. All unnessary services are not permitted through the firewall. This may lead to inefficiency of use. However the security level is also raised. Note that the firewall blocks all unpermitted connections. If you need to set up a server, please apply to the computer center. To access IIS internal resources outside of IIS, you may use the following ways.
  • Email: Use webmail or secure SMTPs, POP3s, IMAPs to access the mail server.
  • If you are not in IIS networks and need to access internal resources, please connect through VPN (server: or Please remember to logout when you finish the job.
  • If you are in IIS networks and have trouble passing through firewall, please connect throught VPN (server: to go across the firewall. Then you can work as usual. Please remember to logout when you finish the job.

You may use MS/Windows VPN Client (default in Windows 2000/XP) or Cisco VPN client (need to be installed additionally) to connnect to the VPN server. You may choose two different communication protocol, PPTP and L2TP, to connect. Another chioce is to use WebVPN to browse all internal webserver via HTTP.

Currently VPN server only provides PPTP. If you cannot connect to our VPN server (maybe due to the firewall setting of your ISP), please try to connect to VPN server using L2TP or install the extra Cisco VPN Client. If you only need to access the your webserver, it is sufficient to do it via WebVPN.

VPN server:
  • External to internal networks
    - VPN Server Windows VPN Client(PPTP, L2TP) and Cisco VPN Client
    - WebVPN:
    - VPN Server Windows VPN Client(PPTP)
  • Internal to external networks
    - VPN Server MS/ Windows VPN Client(PPTP)
Set up VPN:
  1. Microsoft Windows 2000/XP VPN Client Using PPTP
  2. Microsoft Windows 2000/XP VPN Client Using L2TP
  3. Cisco VPN Client for Microsoft Windows
  4. Cisco VPN Clientfor Linux
  5. Cisco VPN Clientfor MacOS
  6. Cisco VPN Client for Solaris
  7. Web VPN
  8. Using PPTP client on Linux

Port setting for VPN:
  • PPTP: TCP Port 1723 and IP Protocol GRE(47)
  • L2TP: UDP Port 500, UDP Port 4500, and IP Protocol ESP(50)
  • Cisco VPN Client: UDP Port 5000, UDP Port 10000, and IP Protocol ESP(50)
  • WebVPN: TCP Port 443
If you have IP sharing hubs or firewall, please make sure the above ports are open in both outgoing and incoming directions.