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HTTP > Configuration > Internet Access Control | Client IP
You can have IWSVA prevent all clients, that are not listed in the Client IP address list, from accessing the Internet.
Specify the IP address or range of IP addresses that you will grant Internet access.
Type a descriptive name in the Description field. (40 characters maximum)
Next, choose Enable HTTP Access Based On Client IP. After enabling, only those users specified there will be able to connect to the Internet. All others are denied.
The following rules apply:
IP entries should be in the a.b.c.d format.
Masks can be in the a.b.c.d format or specified as numbers of bits (0-32).
For entries where the mask is omitted, a default mask of 255.255.255.255 is assumed.
IP
IP start range to end range
IP/IP mask
192.168.0.150 # Only the machine whose IP address is 192.168.0.150
192.168.0.10-192.168.0.20 # Covers machines whose IP falls in the range 192.168.0.10 to 192.168.0.20
192.168.1.0/24 # An alternate of all the machines in 192.168.1.x