User guide

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4.5 Installation without IP Address Change
(One-Armed Out-of-Path Mode)
The above diagram is an example about how to configure the WebMux in Out-of-Path Mode
without changing the IP addresses of the web servers and other servers that already exist on
the network. This is particularly helpful when the changing of an existing network of servers
causes problems.
In this configuration, all the servers still remain on the same IP network and can
communicate. From the servers “view,” the WebMux is on the same network as the servers.
On the WebMux, only the server LAN cable is connected, since there is only one network in
Out-of-Path Mode. The WebMux takes at least two IP addresses to work in this mode, the
server LAN Interface IP address and the farm IP addresses.
If you are connected to a manageable switch that allows you to create Link Aggregation
Groups (LAG), sometimes called “Ether-Channel” or “Port Channel,” the Internet port and
Server port on the WebMux can be connected to the switch and will behave as one logical
port with about twice the bandwidth capabilities. It is important that you configure the switch
properly before connecting both interfaces. Please refer to your switch’s user manual about
creating Link Aggregation Groups.
Two simple changes must be made to each server in the farm. 1) Have a new loopback
adapter installed and have its address set to the farm address. Do not set the gateway on the
loopback adapter. Please refer to Appendix A and Appendix B for how to configure a
loopback adapter, as well as how to remove the route from the servers. Please note for Out-
of-Path Mode to work properly, the loopback adapter must route the return traffic