ZyXEL Communications 2WG - Manual (Page 174)

ZyWALL 2WG Support Notes
All contents copyright (c) 2006 ZyXEL Communications Corporation.
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33. On Shared Secret settings, choose ToZyWALL option, and press Edit button
34. Enter the secret key in the text box, and then press OK button.
35. On Advanced VPN Properties settings, choose Group 1 for Diffie-Hellman settings.