Chapter 26 IP Source Guard

You can configure the name and location of the file on the external TFTP server. The file has the following format:

Figure 128 DHCP Snooping Database File Format

<initial-checksum>

TYPE DHCP-SNOOPING VERSION 1

BEGIN

<binding-1> <checksum-1> <binding-2> <checksum-1-2>

...

...

<binding-n> <checksum-1-2-..-n>

END

The <initial-checksum> helps distinguish between the bindings in the latest update and the bindings from previous updates. Each binding consists of 72 bytes, a space, and another checksum that is used to validate the binding when it is read. If the calculated checksum is not equal to the checksum in the file, that binding and all others after it are ignored.

26.1.1.3 DHCP Relay Option 82 Information

The Switch can add information to DHCP requests that it does not discard. This provides the DHCP server more information about the source of the requests. The Switch can add the following information:

•Slot ID (1 byte), port ID (1 byte), and source VLAN ID (2 bytes)

•System name (up to 32 bytes)

This information is stored in an Agent Information field in the option 82 field of the DHCP headers of client DHCP request frames. See Chapter 37 on page 349 for more information about DHCP relay option 82.

When the DHCP server responds, the Switch removes the information in the Agent Information field before forwarding the response to the original source.

You can configure this setting for each source VLAN. This setting is independent of the DHCP relay settings (Chapter 37 on page 349).

26.1.1.4 Configuring DHCP Snooping

Follow these steps to configure DHCP snooping on the Switch.

1Enable DHCP snooping on the Switch.

2Enable DHCP snooping on each VLAN, and configure DHCP relay option 82.

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metrogigabit switch specifications

ZyXEL Communications has long been a prominent player in the networking hardware industry, providing innovative solutions that cater to both business and consumer markets. Among their notable offerings is the Metrogigabit switch, a device designed to meet the high demands of modern networks.

The ZyXEL Metrogigabit switch is primarily aimed at service providers and large enterprises, recognizing the need for seamless connectivity in an increasingly digital world. This switch is engineered for scalability, enabling users to effortlessly expand their network as their operational needs grow. With support for high bandwidth, it is particularly suited for environments requiring extensive data traffic management, such as data centers and campus networks.

One of the standout features of the Metrogigabit switch is its high-density gigabit Ethernet ports, which provide a backbone for reliable data transmission. The switch typically supports multiple 10G SFP+ uplinks, ensuring fast and efficient connections to upstream devices. This capability allows users to configure their networks to handle large volumes of data quickly and without interruption.

In terms of technology, the Metrogigabit switch leverages advanced Layer 2 and Layer 3 functionalities. This includes features such as VLAN support for traffic segmentation, Quality of Service (QoS) for prioritizing mission-critical applications, and robust multicast management. These capabilities contribute to enhanced network efficiency and performance.

Another characteristic that sets the ZyXEL Metrogigabit switch apart is its built-in security features. The device is designed to protect network integrity through mechanisms like port security, access control lists, and advanced authentication protocols. This focus on security helps prepare businesses to counteract potential threats in a landscape where cyber attacks are increasingly sophisticated.

Moreover, the switch is equipped with a user-friendly management interface, which simplifies the process of monitoring and configuring network settings. This is complemented by support for SNMP and RMON, allowing network administrators to leverage tools for effective performance monitoring.

In summary, the ZyXEL Metrogigabit switch is an essential tool for organizations seeking robust performance, reliability, and security in their networking infrastructure. With its high-density ports, flexible configuration options, and comprehensive management features, it provides a strong foundation for building efficient and scalable networks. Whether for service providers or enterprises, this switch stands out as a reliable choice in the fast-evolving technological landscape.
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