Cisco Cisco Prime Virtual Network Analysis Module (vNAM) 6.3 White Paper

Traffic control and visibility point—CSR provides instrumentation for high-touch application 
visibility and control with features such as Performance Agent for round-trip response time statistics 
collection, AppNav traffic redirection (for example, to performance optimization service appliances), 
Switched Port Analyzer (SPAN), NetFlow, QoS, NAT and Dynamic Host Configuration Protocol 
(DHCP).

Should redundant CSRs be required, Hot Standby Router Protocol (HSRP) can be used to provide 
resiliency between CSR pairs. In this case, it is actually the HSRP VIP interface that would be the default 
gateway for hosts within the container. HSRP route tracking can be defined to insure symmetric traffic 
flows through each CSR.

The Citrix NetScaler VPX virtual service appliance performs SLB and SSL offload services in the 
VMDC VSA 1.0 architecture. As of this writing, the VPX is available in four models, ranging from 200 
Mbps to 3 Gbps maximum throughput, suiting a broad range of performance requirements and use cases. 
This release leverages the 200 Mbps (VPX-200) model. Supported hypervisors as of this writing are: 
vSphere ESXi, Microsoft Hyper-V, and XenServer. This release is based on the vSphere ESXi 
hypervisor. The number of logical network interfaces supported by the VPX is determined by hypervisor 
limits. Currently, for vSphere 5.1 and ESXi hardware version VMX-09, this is a maximum of 10. VPX 
supports IPv4 and IPv6 packets, and can operate in transparent or routed mode. Required VPX-200 
resources are two vCPUs, 2 GB RAM, and 20 GB HD.

Available shortly as an alternative SLB is the Cisco Netscaler 1000v. Also available in a variety of 
license bundles, this version of the Netscaler load balancer differs from the Citrix VPX in the following 
ways:

Sold and supported directly by Cisco, providing administrative benefits of a single point of contact.

Integration into the Nexus 1000v service insertion technology, providing consistent operational 
experience and flexible service delivery.

More details regarding the Netscaler 1000v are available at the following links:

 and

In this release we focus mainly on the VPX load balancing and resilience capabilities, however the VPX 
is quite feature-rich, supporting a broad range of use cases and functionality. The VPX may be installed 
from an OVF and configured via CLI, however further enhancing usability and ease of configuration is 
the browser-based VPX GUI. More detailed information about the VPX is available 

Characteristics of the VPX virtual service appliance-based service attachment implemented in this 
release include:

Virtual network interface card (vNIC)-based attachment at the DVS or Nexus 1000V virtual access 
edge switch.

VPX instance per front-end and back-end zone (zone in Expanded Gold Container).