Security 13-5

Filter priority

Continuing the customs inspectors analogy, imagine the inspectors lined up to examine a package. If the package matches the first inspector’s criteria, the package is either rejected or passed on to its destination, depending on the first inspector’s particular orders. In this case, the package is never seen by the remaining inspectors.

packet

first filter

match?

no

send to next filter

yes

forward

or discard? discard

(delete)

forward

to network

If the package does not match the first inspector’s criteria, it goes to the second inspector, and so on. You can see that the order of the inspectors in the line is very important.

For example, let’s say the first inspector’s orders are to send along all packages that come from Rome, and the second inspector’s orders are to reject all packages that come from France. If a package arrives from Rome, the first inspector sends it along without allowing the second inspector to see it. A package from Paris is ignored by the first inspector, rejected by the second inspector, and never seen by the others. A package from London is ignored by the first two inspectors, so it’s seen by the third inspector.

In the same way, filter sets apply their filters in a particular order. The first filter applied can forward or discard a packet before that packet ever reaches any of the other filters. If the first filter can neither forward nor discard the packet (because it cannot match any criteria), the second filter has a chance to forward or reject it, and so on. Because of this hierarchical structure, each filter is said to have a priority. The first filter has the highest priority, and the last filter has the lowest priority.

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Netopia 4752 manual Filter priority, Forward

4752 specifications

The Netopia 4752 is a versatile networking device that serves as a digital subscriber line (DSL) modem and router, designed to provide high-speed internet connectivity and advanced networking capabilities for home and small office environments. This device is notable for its reliability and ease of use, making it a popular choice among users looking for seamless internet access.

One of the main features of the Netopia 4752 is its support for various DSL technologies, including ADSL and ADSL2+. This compatibility ensures that users can achieve optimal bandwidth and speed, even on legacy DSL lines. The modem’s capability to handle downstream speeds of up to 24 Mbps allows for smooth streaming, gaming, and browsing experiences.

Equipped with a robust built-in router, the Netopia 4752 offers multiple Ethernet ports for direct wired connections, accommodating multiple devices simultaneously. This feature is especially beneficial in environments where multiple users need to access the internet without latency. Additionally, the device supports wireless connectivity, enabling users to connect their laptops, smartphones, and other Wi-Fi-enabled devices effortlessly.

Security is a crucial aspect of the Netopia 4752’s functionality. The device incorporates a built-in firewall and supports various security protocols, including WPA and WPA2, ensuring that users’ data remains protected from unauthorized access. The user-friendly web-based interface facilitates easy configuration of security settings, making it accessible even for those with limited technical knowledge.

The Netopia 4752 also features advanced Quality of Service (QoS) settings that allow users to prioritize bandwidth for specific applications or devices. This capability is crucial for households or offices that demand high performance for video conferencing, streaming services, or online gaming.

In terms of characteristics, the Netopia 4752 boasts a compact form factor, making it easy to integrate into any workspace without occupying much space. Its durable design ensures longevity, providing reliable service over time.

Overall, the Netopia 4752 stands out as a dependable DSL modem and router solution, with its high-speed internet capabilities, security features, and flexible connectivity options suitable for both home and small office users who require efficient and effective internet access.