Add a Phase 1 Transform

You can define a tunnel to offer a peer more than one transform set for negotiation. For example, one transform set might include SHA1-DES-DF1 ([authentication method]-[encryption method]-[key group]) and a second transform might include MD5-3DES-DF2, with the SHA1-DES-DF1 transform as the higher priority transform set. When the tunnel is created, the Firebox or XTM device can use either SHA1-DES-DF1 or MD5-3DES-DF2 to match the transform set of the other VPN endpoint.

You can include a maximum of nine transform sets. You must specify Main Mode in the Phase 1 settings to use multiple transforms.

In the New Gateway dialog box, select the Phase 1 Settings tab.
In the Transform Settings section, click Add.
The Phase 1 Transform dialog box appears.

Screen shot of the Phase 1 Transform dialog box with default values

From the Authentication drop-down list, select SHA1 or MD5 as the type of authentication.
From the Encryption drop-down list, select AES (128-bit), AES (192-bit), AES (256-bit), DES, or 3DES as the type of encryption.
To change the SA (security association) life, type a number in the SA Life text box, and select Hour or Minute from the adjacent drop-down list.
From the Key Group drop-down list, select a Diffie-Hellman group. Fireware XTM supports groups 1, 2, and 5.
Diffie-Hellman groups determine the strength of the master key used in the key exchange process. A higher the group number provides greater security, but more time is required to make the keys. For more information, see About Diffie-Hellman Groups.
Click OK.
The Transform appears in the New Gateway dialog box in the Transform Settings list. You can add up to nine transform sets.
Repeat Steps 2–6 to add more transforms. The transform set at the top of the list is used first.
To change the priority of a transform set, select the transform set and click Up or Down.
Click OK.

Add a Phase 1 Transform

See Also