Figure 14 Key Exchange Settings Dialog Box
Configure the fields as follows:
•Master key perfect forward secrecy (PFS)
Selecting this check box sets the maximum number of IPsec or Quick Mode (QM) negotiations that IKE can perform using an IKE SA to 1. It is equivalent to specifying -maxqm 1 in the ipsec_config add ike command. PFS is computationally expensive and HP recommends that you enable it only in hostile environments. See “Maximum Quick Modes” (page 43) and “Perfect Forward Secrecy (PFS)” (page 43) for more information.
•Authenticate and generate a new key after every: ____ minutes
This field specifies the maximum lifetime for an IKE SA in units of time. It is equivalent to the -lifeargument of the ipsec_add ike command.
TIP: Note that this value is specified in minutes on Windows systems and in seconds on HP-UX systems.
•Authenticate and generate a new key after every: ____ sessions
This field specifies the maximum QM negotiations per IKE SA. It is equivalent to the -maxqm argument of the ipsec_add ike command. See “Maximum Quick Modes” (page 43) and “Perfect Forward Secrecy (PFS)” (page 43) for more information.
Modify the values as appropriate. If you do not want to modify the IKE encryption, hash, or Diffie-Hellman Group parameters, click OK to return to the General dialog box and continue to the next step.
To modify IKE encryption algorithm, hash algorithm, or Diffie-Hellman Group parameters, click Methods. The IP Security configuration utility opens the Key Exchange Security Methods dialog box, which lists IKE algorithms and Diffie-Hellman Groups that correspond to IKE SA proposals in order of preference. You can change the order by using the Move up and Move down buttons. You can also delete IKE SA proposals (such as proposals that use DES, which has been cracked) using the Delete button.
To add another IKE SA proposal (method), click Add.
The IP Security configuration utility opens the IKE Security algorithms dialog box (Figure 15).
