Cisco Cisco Prime Network Services Controller Adaptor for DFA 백서

 

 

© 2016 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information. 

Page 5 of 32 

Clients that access the load-balanced application can be located within the fabric or external to fabric. Figures 2 

and 3 show how application data traffic is load-balanced in the network fabric in this deployment scenario.  

1.  Clients external or internal to the fabric request data from the web application, which can be reached through 

VIP1.  

2.  On the basis of the algorithm configured for the load balancer, the received request is prepared for forwarding 

to one of the real web servers on the configuration list. The load balancer performs a NAT operation and 
swaps out the client’s source IP address in the packet header and swaps in the VIP1 address. This process 

helps ensure that the return traffic passes back through the load balancer. The packet is then forwarded to the 

real server. In most deployment scenarios, VIP addresses and real web servers reside on different subnets. 

Figure 2.    Data Traffic Path in the Fabric: Client to Load Balancer to Web Server Path 

 

3.  When the load balancer receives the return traffic from the web server, the traffic is subjected to SNAT. This 

process helps ensure that the client maintains the TCP session of a current web transaction or the User 

Datagram Protocol (UDP) data stream of a given application. 

4.  The load balancer then forwards the return traffic back to the client.