Configuring VPN
Advanced Configuration of IPSec VPN
Cisco SA 500 Series Security Appliances Administration Guide
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8
•
Enable RollOver:
This option is applicable if you have two ISP links and if
you have enabled Auto-Rollover (see
Configuring Auto-Rollover, Load
Balancing, and Failure Detection, page 65
). In this case, you can check the
Enable RollOver
box to ensure that VPN traffic rolls over to the backup link
whenever the primary link fails. The security appliance will automatically
update the local WAN gateway for the tunnel based on the optional WAN link
configuration. For this type of configuration, Dynamic DNS has to be
configured because the IP address will change due to failover. See
Dynamic
DNS, page 91
.
STEP 4
In the
Local Traffic Selection
area and the
Remote Traffic Selection
area, enter
the following information to specify the IP addresses that are on either side of the
tunnel:
•
Local IP
or
Remote IP:
Choose one of the following options:
-
Any:
Allows all traffic from the given end point. Note that selecting
Any
for both local and remote end points is not valid.
-
Single:
Allows only one host to connect to the VPN. If you choose this
option, also enter the IP address of the host in the Start IP Address field.
-
Range:
Allows all computers within an IP address range to connect to the
VPN. If you choose this option, also specify the range by entering the
Start IP Address and the End IP address.
-
Subnet:
Allows all computers on a subnet to connect to the VPN. If you
choose this option, also enter the network address and the subnet mask.
STEP 5
If you chose Manual Policy for the Policy Type, create an SA (Security Association)
by entering the following static inputs in the
Manual Policy Parameters
area:
•
SPI-Incoming
or
SPI-Outgoing:
Enter a hexadecimal value between 3 and
8 characters. For example: 0a1234.
•
Encryption Algorithm:
Choose the algorithm that is used to encrypt the
data.
•
Key-In:
Enter the encryption key of the inbound policy.
•
Key-Out:
Encryption key of the outbound policy.
The length of the keys depends on the chosen algorithm:
-
DES:
8 characters
-
3DES:
24 characters