Benefits of load balancing Netsweeper
Implementing Loadbalancer.org appliances enables multiple Netsweepers to be deployed in a cluster. This provides the following key benefits:
- Better performance: For additional performance simply add more Web Gateways to the cluster.
- High Availability (HA): If a Web Gateway fails, service is not interrupted.
- Maintenance: Web Gateways can easily be taken out of the cluster for maintenance.
About Netsweeper
Netsweeper is a Linux based web filtering software developed by the Netsweeper corporation. It provides functions for filtering malicious and inappropriate web content, which can help with meeting compliance and regulatory requirements. The software can be installed on hardware or used in a virtual environment, both of which can be load balanced using Loadbalancer.org appliances. Implementing Loadbalancer.org appliances enables multiple Netsweeper software to be deployed in a cluster.
Loadbalancer.org’s web filter expertise helps us to guard against filter failure – ensuring uninterrupted service and excellent user experience.
Why Loadbalancer.org for Netsweeper?
Loadbalancer’s intuitive Enterprise Application Delivery Controller (ADC) is also designed to save time and money with a clever, not complex, WebUI.
Easily configure, deploy, manage, and maintain our Enterprise load balancer, reducing complexity and the risk of human error. For a difference you can see in just minutes.
And with WAF and GSLB included straight out-of-the-box, there’s no hidden costs, so the prices you see on our website are fully transparent.
More on what’s possible with Loadbalancer.org.
How to load balance Netsweeper
The load balancer can be deployed in 4 fundamental ways: Layer 4 DR mode, Layer 4 NAT mode, Layer 4 SNAT mode, and Layer 7 Reverse Proxy (Layer 7 SNAT mode).
For Netsweeper, Layer 4 DR Mode load balancing is recommended. This is a very high-performance solution that is well suited to web filters and proxies. Note that this method requires the ARP problem to be solved and also requires the application running on the real servers to respond to both its own IP address and the VIP. For full details of how to do this, refer to the deployment guide below.
Deployment modes
Three modes of Netsweeper operation are officially supported:
- Explicit Mode: Proxy settings are explicitly set on each client device. Browser settings on client PCs must be changed to point to the virtual service (VIP) on the load balancer.
- Transparent Mode: Policy based routing (PBR) is used at the router/firewall that handles client traffic. These rules at the router/firewall ensure that the required traffic (typically HTTP & HTTPS traffic on ports 80 and 443) is sent transparently to the load balancer.
- Non-Transparent Mode: Proxy settings are explicitly set on each client device. Browser settings on client PCs must be changed to point at the virtual service (VIP) on the load balancer.
Load balancing deployment concept
About Layer 4 DR mode load balancing
One-arm direct routing (DR) mode is a very high performance solution that requires little change to your existing infrastructure.
DR mode works by changing the destination MAC address of the incoming packet to match the selected Real Server on the fly which is very fast.
When the packet reaches the Real Server it expects the Real Server to own the Virtual Services IP address (VIP). This means that you need to ensure that the Real Server (and the load balanced application) respond to both the Real Server’s own IP address and the VIP.
The Real Servers should not respond to ARP requests for the VIP. Only the load balancer should do this. Configuring the Real Servers in this way is referred to as Solving the ARP problem.
On average, DR mode is 8 times quicker than NAT for HTTP, 50 times quicker for Terminal Services and much, much faster for streaming media or FTP.
The load balancer must have an Interface in the same subnet as the Real Servers to ensure Layer 2 connectivity required for DR mode to work.
The VIP can be brought up on the same subnet as the Real Servers, or on a different subnet provided that the load balancer has an interface in that subnet.
Port translation is not possible with DR mode, e.g. VIP:80 → RIP:8080 is not supported. DR mode is transparent, i.e. the Real Server will see the source IP address of the client.
