Cisco Cisco IOS Software Release 12.2(18)SXD

IOS SLB provides the following routing features:

IOS SLB provides the following load-balancing algorithms:

You can specify one of these algorithms as the basis for choosing a real server for each new connection 
request that arrives at the virtual server.

The weighted round robin algorithm specifies that the real server used for a new connection to the virtual 
server is chosen from the server farm in a circular fashion. Each real server is assigned a weight, n, that 
represents its capacity to handle connections, as compared to the other real servers associated with the 
virtual server. That is, new connections are assigned to a given real server n times before the next real 
server in the server farm is chosen.

For example, assume a server farm comprised of real server ServerA with n = 3,  ServerB  with  n = 1,  and 
ServerC with n = 2. The first three connections to the virtual server are assigned to ServerA, the fourth 
connection to ServerB, and the fifth and sixth connections to ServerC.

Assigning a weight of n=1 to all of the servers in the server farm configures the IOS SLB device to use 
a simple round robin algorithm.

General packet radio service (GPRS) load balancing without GPRS Tunneling Protocol (GTP) cause 
code inspection enabled requires the weighted round robin algorithm. A server farm that uses weighted 
least connections can be bound to a virtual server providing GPRS load balancing without GTP cause 
code inspection enabled, but you cannot place the virtual server INSERVICE. If you try to do so,