Regarding the all 1s subnet, a router requires that each routing table
entry include the prefix length so that it can determine whether a
broadcast (directed or all subnets) should be sent only to the all 1s sub 
net or to the entire network. For example, when the routing table does
not contain a mask or prefix length for each route, confusion can occur
because the same broadcast address ( is used for both the
entire network and the all 1s subnet This
issue is illustrated in Figure 14. 
F I G U R E   1 4 .   I d e n t i f y i n g   a   B ro a d c a s t   t o   t h e   A l l   1 s   S u b n e t
a n d   t h e   E n t i re   N e t w o r k
Defining Host Addresses for Each Subnet
According to Internet practices, the host number field of an IP address
cannot contain all 0 bits or all 1 bits. The all 0s host number identifies
the base network (or subnetwork) number, while the all 1s host number
represents the broadcast address for the network (or subnetwork). 
In our current example, there are 5 bits in the host number field of each
subnet address. This means that each subnet represents a block of 30
host addresses (25  2 = 30, note that the 2 is subtracted because the 
all 0s and the all 1s host addresses cannot be used). The hosts on each
subnet are numbered 1 through 30. 
In general, to define the address assigned to Host #N of a particular
subnet, the network administrator places the binary representation of N
into the subnet's host number field. For example, to define the address
assigned to Host #15 on Subnet #2, the network administrator simply
places the binary representation of 15 (011112 ) into the 5 bits of Sub 
net #2's host number field. 
U N D E R S TA N D I N G   I P   A D D R E S S I N G
1 4






 Home | About Us | Network | Services | Support | FAQ | Control Panel | Order Online | Sitemap | Contact

reliable web hosting


Our web partners: Inexpensive Web Hosting Jsp Web Hosting Jsp Web Hosting Cheapest Web Hosting  Java Web Hosting

 Quality Web Templates Dreamweaver Web Templates Frontpage Web Templates

Jsp Web Hosting Cheapest Hosting Cheapest Web Hosting Java Web Hosting Tomcat Web Hosting

Quality Web Hosting Best Web Hosting Java Web Hosting Business web hosting division of Vision Web Hosting Inc.. All rights reserved