Canon LBP7780CX User Manual page 757

When specifying by time
a. Select the [Specify by Time] check box.
b. Enter the time (1 to 65535 minutes).
When specifying by size
a. Select the [Specify by Size] check box.
b. Enter the size (1 to 65535 MB).
NOTE
About PFS
If PFS is used, the key generation process becomes complex. Even assuming one key is deciphered, it does not mean
that later keys will be deciphered easily.
10
Set [Authentication/Encryption Algorithm] under [IPSec Network Settings].
When setting automatically
Select the [Auto] check box.
When setting authentication using ESP protocol
(1) Select the [ESP] check box.
(2) Select the authentication algorithm from [SHA1], [MD5], [SHA1 and MD5] or [NULL] under [ESP Authentication].
(3) Select the encryption algorithm from [3DES-CBC], [AES-CBC], [3DES-CBC and AES-CBC] or [NULL] under [ESP
Encryption].
When setting authentication using AH protocol
(1) Select the [AH] check box.
(2) Select the authentication algorithm from [SHA1], [MD5] or [SHA1 and MD5] under [AH Authentication].
11
Click [OK].