Application Grouping and Real Server Persistence
If your real Web servers have many IP addresses, you can easily create a separate VIP for each real IP address
without individually configuring each VIP. To do so, configure a host range. A host range is a block of contiguous
To configure a host range, you add a VIP and specify how many hosts are in the range. The ServerIron ADX
automatically configures a separate VIP for each host in the range. When you bind the base VIP to the real
servers, the ServerIron ADX associates the VIP with the first real IP address on the server. Subsequent VIPs in
the host range are associated with subsequent real IP addresses on the server. The association is based on the
offset from the base VIP. When a client requests an address in the VIP range, the ServerIron ADX automatically
maps the VIP to a real IP address on a real server based on the address's offset from the base VIP address.
For example, if you define a range using the base VIP 188.8.131.52 and a host range of 10, the ServerIron ADX
maps VIPs 184.108.40.206 – 220.127.116.11 to a range of ten addresses on each real server. If a client requests VIP
18.104.22.168 (two from the base VIP number), the ServerIron ADX sends the request to an IP address that is two
higher than the start of the corresponding range on a real server.
You can configure up to 256 virtual servers, each with a host range of 256 addresses, for a total of up to 64,000
NOTE: To use this feature, the IP address range on the real server must be contiguous. If the range contains
gaps (addresses in use by other hosts), specify separate ranges on the virtual server to work around the gaps.
The "track source-ip" command entered under a VIP acts like enabling stickiness for all protocols defined under
that VIP. This means that all requests from the same source-ip to all destination ports defined in the VIP will be
load balanced to the same real server.
NOTE: This is not a commonly used feature. You can also use "sticky" for each port you define under the VIP.