Canon iR3245 Network Manual page 117

On the Specify by Service Name screen, select a displayed service name →
press [Service On/Off].
3
7. On the Register screen, press [IKE Settings] → select the mode to use
for IKE phase 1.
[Main]: Select to set the Main mode. This mode has strong security because the IKE session
itself is encrypted.
[Aggressive]: Select to set the Aggressive mode. This mode speeds up IKE sessions
because they are not encrypted.
Registering a Security Policy 3-65