Riverstone Networks WICT1-12 - Manual (Page 506)

22-8 Riverstone Networks RS Switch Router User Guide Release 8.0
Load Balancing Web Hosting Configuration
The following example sets the status of port 80 at address 135.142.179.14 to up:
22.1.7 Load Balancing and FTP
File Transfer Protocol (FTP) packets require special handling with load balancing, because the FTP 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 RS to know the port number that is used for FTP. Therefore you need to specify the FTP control port as shown in
the following example:
22.1.8 Allowing Load Balancing Servers to Access the Internet
A load balancing server may need to occasionally make its own request to the Internet in order to complete a client’s
request. For example, a DNS server that is being load balanced may need to send a request to another DNS server on
the Internet to resolve a hostname. To allow Network Address Translation (NAT) for the server’s Internet request (and
the reply), you must specify the port numbers that the load balancing servers will use for these requests.
Following example specifies a range of ports for Internet requests by the “mktgroup” load balancing group:
22.1.9 Allowing Access to Load Balancing Servers
Load balancing causes both source and destination addresses to be translated on the RS. 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.
In the following example, access is allowed to servers in the IP address range of 135.142.179.14 to 135.142.179.21:
22.1.10 Virtual State Replication Protocol (VSRP)
VSRP provides redundancy in a dual load balancer setting. It runs between two RS’s that have the same load balancing
group configured, enabling them to mirror each other’s session information for a particular load balancing group.
VSRP runs in the active-active mode, so the RS’s share persistence information in real time. Thus, should one RS go
down, the other is able to immediately take over.
rs # load-balance set server-status server-ip 135.142.179.14
server-port 80 group-name engservers status up
rs(config)# load-balance set ftp-control-port 10
rs(config)# load-balance set wildcard-lsnapt-range mktgroup
source-port-range 11-15
rs(config)# load-balance allow access-to-servers client-ip
135.142.179.14-135.142.179.21 group-name mktgroup