Security 13-31

and a packet goes through these rules destined for FTP, the packet would pass through the first filter rule (WWW), match the second rule (FTP), and the packet is allowed through. Even though the next rule is to deny all FTP traffic, the FTP packet will never make it to this rule.

Binary representation

It is easiest when doing filtering to convert the IP address and mask in question to binary. This will allow you to perform the logical AND to determine whether a packet matches a filter rule.

Logical AND function

When a packet is compared (in most cases) a logical AND function is performed. First the IP addresses and subnet masks are converted to binary and then combined with AND. The rules for the logical use of AND are as follows:

0 AND 0 = 0

 

 

0 AND 1 = 0

 

 

1 AND 0 = 0

 

 

1 AND 1 = 1

 

 

For example:

 

 

Filter rule:

 

 

Deny

 

 

IP: 163.176.1.15

BINARY:

10100011.10110000.00000001.00001111

Mask: 255.255.255.255

BINARY: 11111111.11111111.11111111.11111111

Incoming Packet:

 

 

IP 163.176.1.15

BINARY:

10100011.10110000.00000001.00001111

If you put the incoming packet and subnet mask together with AND, the result is:

10100011.10110000.00000001.00001111

which matches the IP address in the filter rule and the packet is denied.

Implied rules

With a given set of filter rules, there is an Implied rule that may or may not be shown to the user. The implied rule tells the filter set what to do with a packet that does not match any of the filter rules. An example of implied rules is as follows:

Implied

Meaning

 

 

Y+Y+Y=N

If all filter rules are YES, the implied rule is NO.

 

 

N+N+N=Y

If all filter rules are NO, the implied rule is YES.

 

 

Y+N+Y=N

If a mix of YES and NO filters, the implied rule is NO.

 

 

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Farallon Communications R9100 manual Binary representation, Logical and function, Implied rules
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R9100 specifications

Farallon Communications R9100 is a high-performance network device designed to meet the demanding needs of modern telecommunications. This robust system specializes in delivering reliable, efficient, and scalable solutions for various networking environments. Its architectural design integrates cutting-edge technologies that enhance performance while ensuring compatibility with existing infrastructure.

One of the standout features of the R9100 is its advanced routing capabilities. Equipped with powerful processors, it supports multiple routing protocols, including OSPF, BGP, and EIGRP. This flexibility allows network administrators to optimize data flow and maintain seamless connectivity across diverse network topologies. The R9100 also includes sophisticated Quality of Service (QoS) mechanisms, enabling prioritization of critical traffic, which is essential for latency-sensitive applications.

Another significant aspect of the R9100 is its support for various interfaces. Whether organizations require Ethernet, fiber, or wireless connections, the R9100 accommodates a broad range of interface options. This versatility ensures that it can be deployed in various environments, from large enterprise networks to smaller branch offices.

Security is a crucial consideration in today’s networking landscape, and the R9100 addresses this with built-in security features. These include stateful firewall capabilities, Intrusion Detection System (IDS), and comprehensive Virtual Private Network (VPN) support. Such features allow organizations to safeguard sensitive data and maintain compliance with industry regulations.

The R9100 also prioritizes ease of management. With a user-friendly interface and robust monitoring tools, network administrators can easily configure and manage the device. This capability facilitates rapid troubleshooting and performance tuning, ensuring minimal downtime and optimal user experience.

Energy efficiency is an additional characteristic that sets the R9100 apart from its competitors. Designed with eco-friendly technologies, it minimizes power consumption while maximizing output, making it an ideal choice for organizations looking to reduce their carbon footprint.

In conclusion, Farallon Communications R9100 stands out as a versatile and powerful network device that meets the complexities of modern telecommunications. With its advanced routing features, robust security measures, varied interface options, and energy-efficient design, the R9100 is a formidable player in the networking landscape. Organizations can rely on this solution to enhance their network performance and evolve alongside their growing technological needs.
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