Reconnaissance work on target domain to find out target domain has load balancer so that penetration testing does not misdirect your probs or attacks.So Its recommended to check the domain has Load balancers, Intrusion Prevention system ,Reverse Proxies ,Firewalls or content switches all these things will cause false results on security scans.
- It acts as a reverse proxy which distributes application or network traffic across a number of servers.
- It ensure reliability and availability by monitoring the health of the application and sending request server or application that can respond in timely manner.
- Load balancers are found in 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 target domain.
- Type lbd followed by target domain name.Ex: lbd tamilrockers.pl
- We have found HTTP load balancer & DNS load balancer for tamilrockers.pl domain.
Before we start penetration testing.Its mandatory to do this Reconnaissance work on the target domain to detect possible Network & Application Security devices.
Source : GBHackers