Penetration testing can be internal or external. Internal penetration assesses an
organization’s security posture and identifies security control shortcomings. External
penetration testing examines enterprise perimeter security and detects security control
flaws.
There is another big difference between internal and external network penetration testing:
internal network pen testing is performed by authorized personnel within an organization. In
contrast, external network pen testing is done by authorized parties outside of the
organization.
Perimeter network penetration testing aims to evaluate how effective perimeter security
measures detect and deter attackers. It also spots flaws in internet-facing assets like FTP
servers. Perimeter devices and testing include:
- Firewalls: Assessing firewall security implementation.
- Routers: Examining the security posture before traffic
appearance on an untrusted network.
- Switches: Evaluating switch security.
- IDS devices: Detecting unusual or suspicious activity in
network traffic and alerting the administrator.
- IPS devices: Monitoring malicious activity on a network
and taking action to stop it.