Know your target
The process of gathering information about your target is known as enumeration. The goal is to establish an active connection with the target and find vulnerabilities that can be used to further exploit the system. There are a variety of tools and techniques that can help with the enumeration process. Enumeration can be performed on a variety of internet protocols including, NetBIOS, SNMP, NTP, LDAP, SMTP, DNS, and Windows and Linux systems. The following is some information you want to gather:[5]
Usernames and group names.
Hostnames.
Network shares and services spacebar clicker
IP tables and routing tables.
Service settings and audit configurations.
Applications and banners.
SNMP and DNS details.