Cisco Cisco Web Security Appliance S170 사용자 가이드

When you define multiple external proxies in a proxy group, the Web Proxy can use load balancing 
techniques to distribute requests to different proxies defined in the group. You can choose the following 
load balancing techniques:

None (failover). The Web Proxy directs transactions to one external proxy in the group. It tries to 
connect to the proxies in the order they are listed. If one proxy cannot be reached, the Web Proxy 
attempts to connect to the next one in the list.

Fewest connections. The Web Proxy keeps track of how many active requests are with the different 
proxies in the group and it directs a transaction to the proxy currently servicing the fewest number 
of connections.

Hash based. The Web Proxy uses a hash function to distribute requests to the proxies in the group. 
The hash function uses the proxy ID and URL as inputs so that requests for the same URL are always 
directed to the same external proxy.

Least recently used. The Web Proxy directs a transaction to the proxy that least recently received 
a transaction if all proxies are currently active. This setting is similar to round robin except the Web 
Proxy also takes into account transactions a proxy has received by being a member in a different 
proxy group. That is, if a proxy is listed in multiple proxy groups, the “least recently used” option 
is less likely to overburden that proxy.

Round robin. The Web Proxy cycles transactions equally among all proxies in the group in the 
listed order.

For information about creating Routing Policies, see 

.

If your network contains an upstream proxy that does not support FTP connections, then you must create 
a Routing Policy that applies to all Identities and to just FTP requests. Configure that Routing Policy to 
directly connect to FTP servers or to connect to a proxy group whose proxies all support FTP 
connections. 

To define external proxy information, you create a proxy group. A proxy group is an object that defines 
a list of proxies and their connection information and the load balancing technique to use when 
distributing requests to proxies in the group. You can create multiple proxy groups and can define 
multiple proxies within a group. 

AsyncOS for Web allows you to enter the same proxy server information multiple times into the same 
proxy group. You might want to include the same proxy server multiple times to allow unequal load 
distribution among the proxies in the proxy group.