The F5 BIG-IP appliance IPsec VPN must renegotiate the IKE Phase 2 security association after eight hours or less.

When a VPN gateway creates an IPsec Security Association (SA), resources must be allocated to maintain the SA. These resources are wasted during periods of IPsec endpoint inactivity, which could result in the gateway’s inability to create new SAs for other endpoints, thereby preventing new sessions from connecting. The Internet Key Exchange (IKE) idle timeout may also be set to allow SAs associated with inactive endpoints to be deleted before the SA lifetime has expired, although this setting is not recommended at this time. The value of one hour or less is a common best practice.

From the BIG-IP GUI: 1. Network. 2. IPsec. 3. IPsec Policies. 4. Click on the name of the IPsec Policy. 5. Verify that the value for "Lifetime" under "IKE Phase 2" is set to 480 minutes or less.

If the BIG-IP appliance is not configured to renegotiate the security association after 8 hours or less, this is a finding.

From the BIG-IP GUI: 1. Network. 2. IPsec. 3. IPsec Policies. 4. Click on the name of the IPsec Policy. 5. Configure the value for "Lifetime" under "IKE Phase 2" to 480 minutes or less. 6. Click "Update".