Cabletron Systems SmartSwitch Router, Руководство пользователя

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Chapter 15: Web Hosting Configuration Guide
236 SmartSwitch Router User Reference Manual
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 SSR 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 SSR.
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.
Setting Timeouts for Load Balancing Mappings
A mapping between a host (source) and a load-balancing server (destination) times out
after a certain period. You can specify the timeout for source-destination load balancing
mappings.
To specify the timeout for load balancing mappings, enter the following command in
Configure mode.
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>
Specify the timeout for source-
destination mappings.
load-balance set mappings-age-timer
<timer>