Using NetExtender
Step 9 You may see a Security Error: Domain Name Mismatch warning. Click OK.
Step 10 The Software Installation window is displayed. After a five second countdown, the Install Now button will become active. Click it.
Step 11 You may be prompted to
Step 12 Firefox will restart and you will need to login again. NetExtender will then install as a Firefox extension.
SonicWALL SSL VPN 5.0 User Guide