Network

Node

Class C allows up to approximately 2 million network numbers, and 255 node numbers: Bits 0–2 are 110, bits 3–23 are the network identifier, and bits 24–31 are the node identifier. In dotted decimal notation, the range of Class C addresses is 192.0.0.0–223.255.255.255 .

Node

Network

If the node identifier is all zeroes, the overall 32-bit IP address refers specifically to the network identified by the network identifier. If the host identifier is all ones, the 32-bit address refers to all hosts attached to the network. (This is the IP broadcast address for that network.) If the entire 32 bits are ones, the address refers to all hosts on the local network.

IP addresses are administered by Standford Research Institute’s Network

Information Center (NIC).

Subnet Addressing

Multiple physical networks can use a single IP network address. This is done by using a portion of the node identifier (it does not need to be in complete octets) as a "subnet" identifier. For example, in a Class B network, the first and second octets are the network identifier, and the third and fourth are the node identifier. If the network con- tains the maximum of 65,025 nodes, management will most likely be easier if the third octet of the IP address is used to define up to 255 subnets on the network. The fourth octet can then define up to 255 nodes on each subnet, effectively providing unique identifiers for all 65,025 nodes on the network.

As described earlier, the first octet of the IP address identifies the network’s class: 0–127= A, 128–191= B, and 192–223= C. Once the Internet Protocol knows the class, it knows how many octets are supposed to identify the network and how many are sup- posed to identify the node. When part of the node identifier is used as a subnet iden- tifier, there must be a method of telling IP of the modification. This is done with a subnet mask. The mask is created by taking the 32-bit (binary) IP address, then sub- stituting a 1 for every bit that identifies the network or a subnet, and a 0 for every bit that identifies a node. When IP applies this mask to an actual IP address, it can see which bits identify the subnet and which identify the node. (IP already knows the network’s class, and therefore which bits identify the network.)

Using the Node as an IP Gateway

A SmartSwitch 1800 can function as an IP gateway, and forward IP packets. This requires that IP be configured (and loaded) in the Protocols file (described in Chapter 5).

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1800 specifications

Cabletron Systems, a leading player in network management and telecommunications solutions during the late 20th century, introduced several innovative products that played a crucial role in shaping enterprise networking. Among these were the Cabletron FRX6000, FRX4000, and the FRX1800, which delivered advanced features aimed at enhancing network performance, security, and scalability.

The Cabletron FRX6000 was designed as a robust multi-layer switch, ideal for large-scale enterprise environments. It supported extensive routing capabilities, allowing organizations to manage traffic efficiently even under heavy loads. The FRX6000 boasted high throughput rates and low latency, making it suitable for demanding applications. With support for various network protocols, including IP, IPX, and AppleTalk, its adaptability made it a versatile choice for diverse networking needs. Moreover, security features like VLAN support and Access Control Lists (ACLs) provided enhanced protection against potential threats.

Moving to the FRX4000, this model offered a balance between performance and cost-effectiveness. The FRX4000 maintained many of the essential features of its larger counterpart while catering to medium-sized enterprises. It provided Layer 3 routing and could handle multiple simultaneous connections, ensuring seamless communication across departments. The modular design allowed for easy upgrades, enabling businesses to expand their network infrastructure without significant overhauls. This made the FRX4000 an attractive option for organizations looking to optimize their network investments.

Lastly, the FRX1800, designed for small to medium businesses, focused on simplicity and ease of use while still incorporating powerful network management capabilities. Its user-friendly interface made it accessible for organizations lacking extensive IT resources. The FRX1800 provided essential functionalities such as Integrated Layer 2 switching and routing, network monitoring, and basic security features, ensuring that even smaller companies could maintain efficient, reliable networking without overwhelming complexity.

All three models utilized advanced technologies, including a high bandwidth backbone and state-of-the-art switching architecture, to enable fast and reliable data transfer. They also supported Quality of Service (QoS) mechanisms, allowing businesses to prioritize critical applications and ensure consistent performance across the network.

In summary, the Cabletron FRX6000, FRX4000, and FRX1800 were pivotal in enhancing network capabilities, providing organizations with scalable, secure, and high-performance options tailored to their specific needs.