Adaptec iSA1500 User Guide - Page 26

Introduction to iSCSI and IPSANs Planning Your IPSAN This section outlines the issues and concepts you should understand as you plan your IPSAN. Basic and complex IPSAN configurations are provided as sample solutions. Invalid IPSAN configurations are also included to help you avoid mistakes. What's a Subnet? A subnet (short for subnetwork) is a separate identifiable portion of a network. Typically, a subnet represents all the systems in one building, in one geographical location, or on the same Local Area Network (LAN.) The advantage of dividing a network into subnets is that the network can connect to the Internet using a single shared network address. Because all devices on each subnet share a common component of that network address, subnetting reduces the number of separate network addresses you require. Valid IPSAN Configurations The configuration drawings in this section show valid IPSAN configurations and provide brief descriptions for each. Please take careful note of these Caution statements before you begin configuring your IPSAN: ! Caution: Unless you are an IP networking expert and have an unusual network configuration, never configure any two interfaces on the same system to be on the same subnet. ! Caution: Use caution when using DHCP on more than one interface-both interfaces may end up on the same subnet, depending on the configuration of the DHCP server. (See Caution above.) 2-9