NLB vs Hardware Load Balancingr
Kemp Technologies has been my employer since I started working there. ServersInternetLoadbalancers are used for availability and scaling of the application. The application can scale beyond the capabilities of one server. Through various load balancing algorithms, the load balancer directs traffic to a pool or servers. Additional servers can be added if more resources are required.
Load balancers perform a health check on the application to determine its availability. If the health check fails, load balancers take the application from its pool of available servers. The health check validates that the application is available and the server is added back to the availability pool.
The load balancer sits between the client’s application server and manages the connection. This allows it to perform other functions. The load balancer is capable of performing content switching, providing content-based security such as web application firewalls (WAF), or authentication enhancements such as two factor authentication (2FA).
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What does a load balancer do?
Load balancing provides security, availability, and scalability to the application. The load balancer is a reverse proxy that directs and controls traffic between clients and servers.
Load balancer uses
How does a load-balancer work?
A load balancer acts as a reverse proxy. It presents a virtual IP address (VIP), which represents the client’s application. The client connects with the VIP, and the load balancer determines through its algorithms whether to send the connection to an application instance on a particular server. The connection is monitored and managed by the load balancer throughout the duration.
Imagine a sports agent trying to negotiate a new contract with a star athlete. The agent receives the request from the athlete, and forwards it to the team that is interested. The agent receives information from the team, which he then forwards to the client. This continues for some time until a solution is found.
This is the primary function for the load balancer, server loads balancing (SLB). Based on their role in the conversation, the agent can provide additional functionality. They can decide whether to disclose or deny certain details (security). They might want to verify that the person they are speaking to is the actual athlete (authentication). If the current league is not working out, an agent can refer the discussions to another league based on availability and location (GSLB).
What are the different types of load balancers available?
Understanding the history is key to understanding the different types of load balancers.
Network Server Load Balancing
In the mid-1990s, load balancers were introduced to the market to help with the increasing traffic on the internet. Load balancers were designed to provide basic functionality and pool server resources to meet the demand. The packet header was used to manage connections by the load balancer. They looked at the 5-tuple, which consisted of source IP, destination IP and source port. Source port, destination port, IP protocol, and destination port. This is the entry of the Layer 4 load balancer or network server loadbalancer.
Application Load Balancing
Load balancers evolved with technology. They evolved and began to offer content awareness and content switching. These load balancers looked at the payload of the content and not just the packet header. These load balancers examine the content, such as the URL and HTTP header, to make load balancing determinations. These are Layer 7 load balancers.

NLB vs. Hardware Load Balancingr – Free Guide (2013)