User guide

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4.3 Installation without IP Address Change
(Two-Armed Transparent Mode)
Transparent Mode is another WebMux configuration that allows you to keep the existing IP
addresses of your servers. Like Out-of-Path Mode, the servers and the WebMux will be on
the same IP network. However, physically, the servers will be connected to the WebMux in
the same way they would be for NAT mode, on the server LAN port. The “internet” port on
the WebMux is connected towards the Firewall/Router. In this mode, the WebMux functions
as an Ethernet bridge. Anything connected to its back interface (server LAN) is on the same
network as its front interface (internet/router LAN). If you look at the diagram above, you
will see that the terminals are on the same network as the servers, even though the servers are
“behind” the WebMux. The terminals can communicate with the servers IP directly as if the
WebMux was not there, and vise versa.
When creating a farm, choose a unique farm IP address in the network, and then add the
server IP address under that farm. Load balancing occurs when the “Farm IP” is accessed
instead of the servers’ actual IP.
There are no configuration changes that need to be made on the servers, only the way they are
physically connected to the network.
The diagram also gives an example of a redundant WebMux setup. In this case, it is
absolutely required that the WebMuxes are connected in between two switches. In the
earlier version firmware, WebMux depends on STP (spanning tree protocol) to avoid packet
looping. From 8.7.xx, WebMux does not require switches supporting STP any more.
During a failover situation, you may immediately notice that the backup becomes
unreachable though the Internet LAN side. In firmware older than 8.7.09, you may notice the
server LAN side not accessible.