Citrix Netscaler 10 Summary Notes – Day 1 and 2

Citrix Netscaler Introduction

It is an application delivery controller. It is a physical or virtual appliance that is used to control application delivery in a network.

Optimizes delivery of the following services:

  • Web applications
  • Cloud based services
  • Virtual desktops
  • Mobile services
  • Business applications

What does it do:

  • Accelerate application delivery up to 5 times
  • Layer 4 to 7 traffic management
  • Has an intergrated firewall that can be used to increase security
  • Increases web server efficiency

Placement in the network:

Infront of application and database servers

What Citrix Netscaler can achieve:

  • High-speed load balancing and content switching
  • Application aceleration
  • Data compression
  • SSL acceleration
  • Network optimization
  • Application performance monitoring
  • Application security

When Netscaler can be used (Application delivery pain points):

  • To ensure application availability
  • To improve performance of certain applications inorder to meet the rise in demand of the application
  • When the infrastructure load is increasing and scalability turns out to be a major concern
  • When there is need to adopt a multilayered security approach to protect information that traverses the network
  • Scalability
  • In readiness of cloud computing

Features offered by NetScaler

a) Application Availability Features:

These features ensure that the applications are always available

  • Load Balancing – Traffic is managed at the request level.
  • Content Switching – Can determine the which server can best respond and switches requests to it.

b) Application Visibility:

Offers application visibility and policy management

  • AppExpert policy manager – For management of all application delivery capabilities. Includes AppVisualizer that provides a graphical display.
  • ActionAnalytics – Intergrated real time monitoring of traffic
  • AppFlow – Generate detailed application flow records
  • EdgeSight – Monitors end-user experience

c) Offload Features: Increase performance demands

These features improve performance.

  • SSL Offloading – Offloads SSL encryptions and decryption from the webservers hence freeing resources
  • Cache redirection – Traffic is sent to reserve proxy. Non-chacheable requests are sent directly to the origin servers over persistanct connections hence reducing response delays
  • TCP Buffering – Adds a speed-matching mechanism between a slow client’s network and a fast server network by buffering the response of the server before delivering it to the client at a slower speed. Retransmissions are also done by NetScaler

d) Optimization features:

Reduces load in the network.

  • TCP Optimization – Some TCP tasks are moved from the servers to Netscaler hence reduced CPU load
  • AppCompress – Compresses HTML and text files using GZip. Upto 50% bandwidth savings
  • AppCache – On-board cache stores results of incoming requests for subsequent requests for the same information hence reducing page regeneration times.
  • WAN Optimization – No reconfiguration is required in network devices when netscaler is present

Security Features:

  • Content Filtering – Protects websites from malicious attacks on layer 7. Screens unwanted requests and reduces server exposure attacks
  • Application Firewall – Filters traffic between servers and end users
  • DNS Security Extensions – Data integrity and data origin authentication between servers and clients
  • AAA Application Traffic – Verifys clients credentials and only allows approved users to access the servers
  • SSL VPN – The Access Gateway can be used to deliver secure remote access for applications and virtual desktops
  • SAML (Security assertion Markup Language) 2.0 – enables single sign-on

New Features in Netscaler 10

  • Application delivery using load balancing and content caching
  • TriScale – Improves network performance by scaling the network up for elastic performance, IN for simplicity and out for expandability. Clustering enables scaling out – Up to 32 appliances can be clustered together (both physical or virtual). The netscaler SDX appliance enables to Scale in by consolidating multiple independently managed appliances into one platform
  • NextGeneration security + SSL and SSL VPNs
  • Action  Analytics – Collects data info from the network
  • Cloud connectivity – Can still control and secure applications even when they are in the cloud
  • Application Visibility – provides end to end monitoring

Netscaler Editions:

* Standard

  • Load Balancing
  • Content Switching
  • Rate Controls
  • IPv6 Support
  • Client and server Side TCP optimization
  • Denial of Service
  • Content Filtering
  • HTTP rewrite modules

* Enterprise – Adds the following to the standard edition

  • Global server Load Balancing
  • Dynamic routing
  • Surge protection
  • Priority queuing
  • Data  compression
  • Citrix Command Center for simplified management of several Netscalers

* Platinum – Adds the following to the Enterprise Edition:

  • Web Application firewall
  • AppCache module used to accelerate applications
  • EdgeSight – end to end visibility of web apps

Netscaler Installation 

Netscaler system can be installed in the following modes:

  • Layer 2 Bridge
  • Layer 3 Router
  • Combnation of modes

Netscaler placement:

Servers -> Netscaler -> Internet -> Clients


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