Cabletron Systems EMM-E6 Ethernet manual Addressing Example

REVIEW OF ADDRESSING

1.10.8Addressing Example

A network manager, planning for the configuration of a network of 60 hosts, desires to implement subnets to create logical divisions between different groups of workstations and devices. The Internet Assigned Numbers Authority has supplied the company with a Class C Network Address; 222. 131. 99. XXX.

Examining Table 1-6 for subnet masking forms, the Network Manager decides that, due to the extent of subnetting to be implemented, the last option in the subnet table is not realistic, as that configuration offers only two subnets. Likewise, the first three options are unacceptable, as they would create an excessively large number of subnets with relatively few individual hosts per subnetwork. This leaves decimal masks of 248 (31 subnets, 6 hosts each), 240 (15 subnets, 14 hosts each), and 224 (6 subnets, 30 hosts each). Any of these decimal masks would support the number of Host IDs to be configured. Looking ahead, the Network Manager realizes that adding Host IDs to a full network can involve a total reconfiguration of subnet strategies, and opts for the decimal mask 240, which provides room for the configuration of 210 Host IDs.

NOTE

On any subnet, one Host ID must be reserved for a connection to the router(s) which will interconnect multiple subnets.

After taking time to fully plan and delineate the required subnets, assign them to departments within the company, plan out the initial Host IDs for existing devices within those subnets and configure the router(s) which will interconnect the various subnets, the Network Manager determines where on the network the network management station will reside. The IP Host ID of this network management station will be essential when configuring the network devices for sending SNMP Traps.

EMM-E6 User’s Guide 1-31