blank.gif (43 bytes)

Church Of The
Swimming Elephant

Binary Hierarchy Connected: An Internet Encyclopedia
Binary Hierarchy

Up: Connected: An Internet Encyclopedia
Up: Programmed Instruction Course
Up: Subnetting and CIDR
Prev: Hierarchical Addressing
Next: Address Prefix Syntax

Binary Hierarchy Like zip codes and telephone numbers, IP addresses are assigned in a hierarchical fashion. Unlike zip codes and telephone numbers, IP addresses are designed to be interpreted by computers, which operate on a binary numbering system, so IP addresses are organized into a binary hierarchy.

Therefore, to understand IP addressing, it is necessary to convert IP addresses into binary, as in this example with the address Each of the four components in the dotted decimal IP address is converted into eight binary bits.

The first sixteen bits, corresponding to the 128.8 portion of the address, are a unique prefix identifying the University of Maryland. A router outside of the University would require only a single routing table entry, indicating that any address beginning with the sixteen bits 10000000 00001000 (in decimal, 128.8) should be sent towards UMD.

Having reached the University of Maryland, a further routing decision must be made, using some or all of the remaining bits. In this case, a routing table entry matches the first twenty four bits 10000000 00001000 01001010 (128.8.74 decimal) and directs the packet towards Worchester Hall.

The router at Worchester Hall discovers that one of its Ethernet interfaces (for example), is configured to match the twenty four bit prefix 10000000 00001000 01001010. At this point, the layer three routing process is complete, since the packet is now in the hands of a router with an interface configured to match the destination address. The final destination should be directly reachable via that interface, so the router relies on a layer two protocol such as ARP to resolve the IP address into an Ethernet address and complete delivery.

Next: Address Prefix Syntax

Connected: An Internet Encyclopedia
Binary Hierarchy


Protect yourself from cyberstalkers, identity thieves, and those who would snoop on you.
Stop spam from invading your inbox without losing the mail you want. We give you more control over your e-mail than any other service.
Block popups, ads, and malicious scripts while you surf the net through our anonymous proxies.
Participate in Usenet, host your web files, easily send anonymous messages, and more, much more.
All private, all encrypted, all secure, all in an easy to use service, and all for only $5.95 a month!

Service Details

Have you gone to church today?
All pages ©1999, 2000, 2001, 2002, 2003 Church of the Swimming Elephant unless otherwise stated
Church of the Swimming Elephant©1999, 2000, 2001, 2002, 2003 is a wholly owned subsidiary of Packetderm, LLC.

Packetderm, LLC
210 Park Ave #308
Worcester, MA 01609