Load Balancer – How Does it Work With Reconnaissance Phase During Penetration Testing?

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:

• 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.