3Com 3C840 Network Router User Manual


 
IP Addressing Basics
B-7
2xx.xxx.188.176, and the subnet mask, 255.255.255.248, together to
determine the number of addresses we had to work with.
First, we convert the last octet (the eight-bit decimal equivalent) of the IP
address (176) and the last octet of the subnet mask (248) to binary:
176
248
The 0s in the subnet mask define our address range, and their three
binary positions (23) yield eight addresses. The addresses that contain all
zeroes and all ones (2xx.xxx.188.176 and 2xx.xxx.188.183,
respectively--see the table below) are reserved as broadcast addresses and
cannot be used.
Also, we were told that 2xx.xxx.188.177 would be assigned to the
OfficeConnect Remote 840's LAN interface, so we can't assign it to any
other computer(s) on the LAN.
Table B-2 IP Addresses
IP Numbered and
Unnumbered Links
The OfficeConnect Remote 840 supports two types of IP addressing on
the Remote Site links: numbered and unnumbered. A numbered link
Last Octet (In
Binary)
Last Octet (In
Decimal) Status
10110 000 176 Reserved - broadcast address
10110 001 177 To be assigned to OfficeConnect Remote 840
10110 010 178 Available
10110 011 179 Available
10110 100 180 Available
10110 101 181 Available
10110 110 182 Available
10110 111 183 Reserved - broadcast address
840ug.book Page 7 Friday, July 7, 2000 2:23 PM