Load Balancer basically helps to distribute the network traffic across the multiple servers to improve the network, application performance. the Reconnaissance work on target to find out target domain has a load balancer so that penetration testing does not misdirect your probs or attacks.
So Its recommended to check the domain has a Load balancer, Intrusion Prevention system, Reverse Proxies, Firewalls or content switches all these things will cause false results on security scans.
- Load Balancer acts as a reverse proxy which distributes application or network traffic across a number of servers.
- It ensures reliability and availability by monitoring the health of the application and sending a request server or application that can respond in a timely manner.
- Load balancers are found in the network and transport layer (IP, TCP, FTP, UDP) and application layer (HTTP)
Standard Industry algorithm:
- Round-robin load balancing is one of the simplest methods for distributing client requests across a group of servers. Going down the list of servers in the group, the round-robin load balancer forwards a client request to each server in turn.
- Does not always result in the accurate or efficient distribution of traffic, because many round-robin load balancers assume that all servers are the same: currently up, currently handling the same load, and with the same storage and computing capacity.
- Weighted round robin – A weight is assigned to each server based on criteria chosen by the site administrator, most commonly used criterion is the server’s traffic-handling capacity.
- Least Connections: If two servers in a cluster have exactly the same specification, one server can still get overloaded considerably faster than the other.
- Random Connections: load balancer receives a large number of requests, a Random algorithm will be able to distribute the requests evenly to the nodes.
Load Balancer Check:
- Above figure illustrator that we have successfully found the Loadbalancer on the target domain.
- Type lbd followed by the target domain name.Ex: lbd tamilrockers.pl
- We have found HTTP & DNS load balancers for tamilrockers.pl domain.
Before we start penetration testing. It’s mandatory to do this Reconnaissance work on the target domain to detect possible Network & Application Security devices.