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Table Of Contents
Installing to an Existing IP Network
Installing to an Unconnected Network
IP Addresses
Internet Protocol (IP) addresses are composed of 4 bytes. The convention is to write addresses in what is called dotted decimal notation. In this form, each byte is converted to a decimal number (0-255), dropping any leading zeros (unless the number is zero) and written with each byte separated by a "." character. By convention, each interface of a host or router has an IP address. It is legal for the same IP address to be used on each interface of a single machine, but usually each interface has its own address.
IP networks are contiguous sequences of IP addresses. All addresses within a network have a number of digits within the address in common. The portion of the address that is common across addresses in the network is called the network portion of the address. The remaining digits are called the host portion. The number of bits that are shared by all addresses within a network is called the netmask and it is the role of the netmask to determine which addresses belong to the network and which do not. See Table B-1 for address type examples.
Any address that is "bitwise anded" with its netmask will reveal the address of the network it belongs to. The network address is therefore always the lowest numbered address within the range of addresses on the network and always has the host portion of the address coded all zeroes.
The broadcast address is a special address that every host on the network listens to in addition to its own unique address. This address is the one that datagrams are sent to if every host on the network is meant to receive them. Certain types of data (like routing information and warning messages) are transmitted to the broadcast address so that every host on the network can receive the data simultaneously. There are two commonly used standards for what the broadcast address should be. The most widely accepted one is to use the highest possible address on the network as the broadcast address. In the example above, this would be 192.168.110.255. For some reason, other sites have adopted the convention of using the network address as the broadcast address. In practice it does not matter very much which you use, but you must make sure that every host on the network is configured with the same broadcast address.
For administrative reasons, early in the development of the IP protocol, some groups of addresses were formed into networks and these networks were grouped into what are called classes. These classes provide a number of standard size networks that can be allocated. Table B-2 shows the allocated ranges.
The addresses you use depend on exactly what it is that you are doing. You may have to use a combination of the following activities to get all the addresses you need.
Installing to an Existing IP Network
To install the NEMI onto an existing IP network, contact the network administrator and ask for the following information:
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Host IP address
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When you have all the information, configure the NEMI with these settings.
Installing to an Unconnected Network
For safety and consistency reasons, these IP network addresses have been reserved specifically for installing hardware on an unconnected network. These addresses are specified in RFC 1918 and are shown in Table B-3.
Decide how large a network you need, and then choose the number of addresses you require.
Posted: Tue Apr 26 05:57:49 PDT 2005
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