LANs, WANs, WLANs are known as edge networks
May be contained within businesses or homes
Needs to be protected from the rest of the Internet!
Cannot stop malicious packets from getting into an edge network
Can determine whether an incoming IP packet comes from a trusted user
However, not all host computers have resources to run authentication algorithms
Host computers managed by different users with different skill levels.
In this module, students will learn how to determine threats and analyze risks to
network perimeters. Students will also learn how to design security for network
perimeters, including screened subnets, and for computers that connect directly
to the Internet.
The need for complete network security has never been greater nor as well understood. Malicious users
threaten to steal, manipulate, and impede information. Numerous solutions address perimeter defense,
but the greatest threat of information theft and unauthorized access remains within the internal network
One point of concern is the relative ease of physical and logical access to a corporate network. Both
physical and logical access has been extended to enable a greater level of mobility, providing several
benefits to business operations and overall productivity.
Chapter 8 - Network security topologies. Objectives in this chapter: Explain network perimeter’s importance to an organization’s security policies, identify place and role of the demilitarized zone in the network, explain how network address translation is used to help secure networks, spell out the role of tunneling in network security, describe security features of virtual local area networks.
This module provides students with the knowledge and skills to configure
Microsoft® Internet Security and Acceleration (ISA) Server 2000 as a firewall.
After completing this module, students will be able to:
Secure the ISA Server computer.
Explain the use of perimeter networks.
Explain the use of packet filtering and Internet Protocol (IP) routing.
Configure packet filtering and IP routing.
Configure application filters.
Perimeter security solutions control access to critical network applications, data, and services so that only legitimate users
and information can pass through the network. This access control is handled by routers and switches with access control
lists (ACLs) and by dedicated ﬁrewall appliances. A ﬁrewall provides a barrier to trafﬁc crossing a network’s “perimeter”
and permits only authorized trafﬁc to pass, according to a predeﬁned security policy. Complementary tools, including virus
scanners and content ﬁlters, also help control network perimeters.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Perimeter Coverage Scheduling in Wireless Sensor Networks Using Sensors with a Single Continuous Cover Range
Most of us have a problem. We are under attack. At this very moment, our internet-connected
computer systems are being subjected to a surprising number of probes, penetration attempts, and
other malicious attention.
In this talk, we will discuss the types of attacks that are being used against our computers, and how to
defend against these attacks.
Network connections should therefore be protected, at a level based on the
risk. The assumption must be that the connecting parties are to a certain degree
hostile and have to be strictly constrained to the access for which the connection
was agreed. The connecting parties will, after all, have their own security
policies and risk management philosophies, and these may vary considerably.
Each security management domain will need to apply stringent logical access
controls, and should strongly consider using firewalls and related technologies to
defend their 'perimeter'....
Static Network Address Translation (NAT) creates a permanent, one-to-one mapping between an address
on an internal network (a higher security level interface) and a perimeter or external network (lower
security level interface). For example, to share a web server on a perimeter interface with users on the
public Internet, use static address translation to map the server’s actual address to a registered IP address.
Static address translation hides the actual address of the server from users on the less secure interface,
making casual access by unauthorized users less likely.
Our approach to deﬁning a security protocol for sensor networks is resource driven and factors in the trade
offs between levels of security and the requisite power and computational resources. Primarily, we envision a
scenario where a protected perimeter based on sensors is dynamically deployed. However, similar scenarios could
be envisioned in an environment where the topology is well known in advance and the sensor network is pre-
conﬁgured. Our operating paradigm is where data is reported to a computationally robust central location such as
a base station or network controller....
The Secretary faces a number of threats. Physical threats include poisoning from radiation, chemical or bi-
ological toxins. These threats are in addition to threats from explosives and individuals utilizing small arms or
other military ordinance. More insidious threats are posed by collection efforts aimed at both the substance of the
Secretary’s agenda and those aimed at analyzing security controls in order to compromise them in order to harm
the Secretary at some later time.
Intrusion detection systems and vulnerability scanners provide an additional layer of network security.While ﬁrewalls permit
or deny trafﬁc based on source, destination, port, or other criteria, they do not actually analyze trafﬁc for attacks or search
the network for existing vulnerabilities. In addition, ﬁrewalls typically do not address the internal threat presented by
IDC believes that multilayered security solutions offer enterprises a cost-effective and
multifaceted alternative to enhance overall infrastructure security posture and improve
customer and management confidence levels. By adopting an overwatch architecture
with additional security layers that detect and remediate threats that have bypassed
perimeter and content security, security managers can reduce the risks of breaches
and infections associated with existing unknown security gaps and vulnerabilities.
Chương 6: Cài đặt và cấu hình DNS Server với chức năng Caching-only trên Perimeter Network Segment
DNS servers hỗ trợ cho các Clients giải quyết Name ra IP addresses. Khi các Computers dùng các ứng dụng Internet (Web, mail, FTP, Chat, Game Online, Voice over IP..), luôn cần phải biết IP address của các Internet Server trước khi có thể connect đến những Server này.
Chương 12: Xuất bản Web và FTP Server thuộc Perimeter Network ra Internet
ISA Server 2004 firewalls cho phép chúng ta publish các nguồn tài nguyên thuộcc các Mạng được bảo vệ, nhằm cho phép người bên ngoài -external users, có thể truy cập đến các nguồn tài nguyên đó. Có 2 phương pháp cơ bản để thực hiện publish các tài nguyên trên các Mạng được bảo vệ là:
Private Link is no longer supported in the PIX Firewall starting with version 5.0. It is supported in
version 4. The Private Link feature allows Virtual Private Networks (VPNs) to be established between
PIX Firewalls that are connected to the same public network, such as the Internet. It enables incoming
Private Link packets to bypass the Network Address Translation (NAT) and Adaptive Security Algorithm
(ASA) features and terminate on the corresponding sending interface of the destination network. A
sending interface is the interface from which the IPSec packet was sent from.