Yaskawa SmartTrac AC1 - Manual (Page 53)

SMART TRAC AC1
Technical Manual TM 3554-000 Networking the Smart Trac AC1
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If on a private network (intranet) you may use any valid Class A, B, or C
address, described below. Most other LANs fall into one of these address classes
and are assigned by the corporation's LAN Administrator.
Any device that connects directly to the internet (not through a "proxy" server)
must be assigned a network ID from the Internet Network Information Center
(InterNIC at www.internic.com). Smart Trac AC1s do not fall into this category.
TCP/IP addresses are grouped into five classes, from Class A through Class E.
The first octet of the IP address specifies its classification.
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Class A – First octet is between 1 and 126 (0 is not allowed, 127 is
reserved as "loopback" address). Organizations with a very large
number of hosts (networked devices) require a Class A address.
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Class B – First octet is between 128 and 191. Large organizations with
as many as 65, 534 networked devices (workstations, printers, routers,
etc) require at least a Class B address.
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Class C – First octet is between 192 and 223. A network with less than
255 networked devices may be assigned a Class C address.
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Class D – First octet is between 224 and 239. These addresses are for
multicast groups, such as RealAudio and Microsoft NetShow.
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Class E – First octet is between 240 and 247. These addresses are
reserved for experimental purposes.
A Subnet Mask defines the split between network and host (device) parts of the
TCP/IP address. It identifies the network octets of the IP address with the
number "255" or "252" and the host octets with the number "0". This defines the
maximum number of different devices (hosts) allowed on the network. A subnet
mask of 255.255.255.0, then, identifies the first three octets of the IP address as
network parts and the last as a single host part. The use of "252" provides one or
more bits of additional resolution for hosts.
Example: The address 200.20.16.5 with a subnet mask of 255.255.0.0 identifies
a network with (255*255)-2 hosts, or 65,534 hosts (two is subtracted to allow
for reserved numbers) on the network identified as "200.20".
Fortunately, Microsoft's Windows NT assigns a default subnet mask to an IP
address. It can be changed if necessary. The defaults result in the following
maximum number of networks and hosts allowed per TCP/IP address:
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Class A – 126 networks, 16,777,214 hosts (default subnet
mask=255.0.0.0).
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Class B – 16,384 networks, 65,534 hosts (default subnet
mask=255.255.0.0)
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Class C – 2,097,152 networks, 254 hosts (default subnet
mask=255.255.255.0)
The Gateway Address provides the IP address to which packets of data should
be sent to route them to their final destination, if on a large enterprise-wide LAN
or the internet. While the Smart Trac AC1 allows you to change the gateway
address to any required, the default of no address will work in nearly all
situations. In enterprise-wide LANs the default may not be acceptable. Contact
your LAN Administrator to determine the proper gateway address.
TCP/IP Address
Classes
TCP/IP Subnet Masks
The Gateway Address