User Manual

Load Balancing
350 Enterasys X-Pedition User Reference Manual
closure of the connection. The following command shows an example of how to send a specific
string to close a connection on a server:
Virtual IP Address Ranges
ISPs who provide web hosting services for their clients require a large number of virtual IP
addresses (VIPs). The load-balance create vip-range-name and load-balance add host-to-vip-
range commands were created specifically for this. An ISP can create a range of VIPs for up to an
entire class C network with the load-balance create vip-range-name command. Once the vip-
range is in place, the ISP can then create the corresponding secondary addresses on their destination
servers. Once these addresses have been created, the ISP can add these servers to the vip-range with
the load-balance add host-to-vip-range command. These two commands combined help ISPs
take advantage of web servers like Apache which serve different web pages based on the
destination address in the http request. The following example illustrates this:.
load-balance set group-options quick-smtp acv-quit “quit”
Router
S1
10.1.1.16 www.computers.com
10.1.1.17 www.dvd.com
10.1.1.18 www.vcr.com
Internet
Web requests:
207.135.89.16 www.computers.com
207.135.89.17 www.dvd.com
207.135.89.18 www.vcr.com
S2
10.1.2.16 www.computers.com
10.1.2.17 www.dvd.com
10.1.2.18 www.vcr.com
...
...
...
10.1.1.50 www.toys.com
10.1.2.50 www.toys.com
207.135.89.50 www.toys.com
Group Name Virtual IP TCP Port
Destination
Server IP
TCP Port
www.computers.com 207.135.89.16 80 S1: 10.1.1.16
S2: 10.1.2.16
80
www.dvd.com 207.135.89.17 80 S1: 10.1.1.17
S2: 10.1.2.17
80
www.vcr.com 207.135.89.18 80 S1: 10.1.1.18
S2: 10.1.2.18
80
www.toys.com 207.135.89.50 80 S1: 10.1.1.50
S2: 10.1.2.50
80