User Manual

Load Balancing
346 Enterasys X-Pedition User Reference Manual
Setting Server Status
It may become necessary at times to prevent new sessions from being directed to one or more load
balancing servers. For example, if you need to perform maintenance tasks on a server system, you
might want new sessions to temporarily not be directed to that server. Setting the status of a server
to “down” prevents new sessions from being directed to that server. The “down” status does not
affect any current sessions on the server. When the server is again ready to accept new sessions,
you can set the server status to “up.”
To set the status of a load balancing server, enter the following command in Enable mode:
Load Balancing and FTP
File Transfer Protocol (FTP) packets require special handling with load balancing, because the FTP
PORT command packets contain IP address information within the data portion of the packet. If the
FTP control port used is not port 21, it is important for the X-Pedition to know the port number that
is used for FTP.
To define an FTP control port (other than port 21) to the load balancing function, enter the
following command in Configure mode:
Allowing Access to Load Balancing Servers
Load balancing causes both source and destination addresses to be translated on the X-Pedition. It
may be undesirable in some cases for a source address to be translated; for example, when data is to
be updated on an individual server. Specified hosts can be allowed to directly access servers in the
load balancing group without address translation. Note, however, that such hosts cannot use the
virtual IP address and port number to access the load balancing group of servers.
To allow specified hosts to access the load balancing servers without address translation, enter the
following command in Configure mode:
Set status of load balancing server.
load-balance set server-status server-ip <ipaddr/range>
server-port <port number> group-name <group name>
status up|down
Specify the FTP control port. load-balance set ftp-control-port <port number>
Specify the hosts that can access
servers without address translation.
load-balance allow access-to-servers client-ip
<ipaddr/range> group-name <group name>