ICS-SCADA Exam Dumps : ICS/SCADA Cyber Security Exam

IPsec offers two modes of operation: Transport mode and Tunnel mode.

Transport mode in IPsec provides security for the payload (the message part) of each packet along the communication path between two endpoints.

In this mode, the IP header of the original packet is not encrypted; it secures only the payload, not protecting the headers. This means while the data is protected, information about the sender and receiver as contained in the IP header is not obscured.

References

"Security Architecture for IP," RFC 4301.

IPsec documentation, Internet Engineering Task Force (IETF).

Ingress filtering is a method used in network security to ensure that incoming packets are allowed or blocked based on a set of security rules.

This type of filtering is often implemented at the boundaries of networks to prevent unwanted or harmful traffic from entering a more secure internal network.

The term "ingress" refers to traffic that is entering a network boundary, whereas "egress" refers to traffic exiting a network.

References

Cisco Networking Academy Program: Network Security.

"Understanding Ingress and Egress Filtering," Network Security Guidelines, TechNet.

The Modbus protocol was developed by Modicon, now a brand of Schneider Electric.

It was originally designed in 1979 for use with its programmable logic controllers (PLCs) in industrial applications.

Modbus is a serial communications protocol that has become a de facto standard communication protocol and is now commonly used to connect industrial electronic devices. The main reasons for its use are its simplicity and the fact that it is open-source, which allows manufacturers to build their own implementations of the standard.

References

"Modbus Protocol Reference Guide," Modicon, Inc., 1979.

"A Guide to the Modbus Protocol," Schneider Electric.