Transcript Document 769202

Wireless Networking
Wireless Standards
802.11a
802.11b
802.11g
802.11n
Traditional IP addresses are 32-bits long and written in dotted decimal
format. These are considered IPv4 format addresses.
172.17.100.203
Since there are only approximately 4.2 billion public IPv4 addresses available
(232), the number of available IP addresses will soon be depleted. That is why
the world will be switching over to the IPv6 system soon.
3ffe:1900:4545:0003:0200:f8ff:fe21:67cf
The IPv6 addresses are 128 bits long, written in hexadecimal, and separated
by colons (similar to MAC addresses, just longer)
There will be 340,282,366,920,938,463,463,374,607,431,768,211,456
IPv6 addresses available (2128) or approximately 340 Undecillion.
Private IP Addresses
A private IP address is an address that is allowed to travel across an internal
network, but not permitted to travel across the Internet. This allows
individuals and companies to have a lot of computers internally, but only
require one or more public IP address, preserving the number of available IP
addresses.
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
169.254.0.0 through 169.254.255.255 (Automatic Private IP Addressing only)
Identify Your Public and Private IP Address
If you are using a Windows-based system, use
the IPCONFIG command to display your current
TCP/IP configuration details. To run the
IPCONFIG command, start a Command Prompt
session (click on Start, then choose [Run], then
[Programs], then [Accessories] and finally
[Command Prompt]). You should get a new
command window. In this window, type
IPCONFIG and press <Enter>.
If you are using a Mac-based system, the
command is IFCONFIG. Click on [Go], then
[Utilities] and then [Terminal]. In the Terminal
window, type the command IFCONFIG.
Follow The OSI Model
In the TCP/IP data flow, the
information flows down and back
up following the Open Systems
Interconnection (OSI) Model.
For this class, we are primarily
concerned with Layers 1-4:
Ethernet/Network cables and
wireless signals operate at Layer 1.
Switches communicate at Layer 2.
Routers/Firewalls communicate at
Layers 3 and 4.
Why Binary and Hexadecimal?
Follow the path . . . .
Internet
Computer
Switch
Router
Why Binary and Hexadecimal?
On the LAN, the wireless or wired Network Interface Card (NIC) on
the computer is identified by the switch by Media Access Control
(MAC) Address which is displayed in hexadecimal format.
Computer
e0:f8:47:aa:ba:81
Switch
00:10:aa:a1:2b:cc
Why Binary and Hexadecimal?
On the LAN, the NIC on the switch is identified by the internal NIC on
the router by the MAC Address
Router
Switch
00:10:aa:a1:2b:cc
01:a0:cc:a4:4e:11
Why Binary and Hexadecimal?
Some routers, like the ones that are in the typical home, have a
switch and router combined into one device.
Why Binary and Hexadecimal?
On the WAN, the external facing NIC on the router is identified by
other computers on the Internet by Internet Protocol (IP) Address,
which is displayed in dotted decimal format, but actually travels
across the Internet in binary format.
Internet
Router
216.54.111.220
128.122.108.71
10000000.01111010.01101100.01000111
Why Binary and Hexadecimal?
Follow the path . . . .
128.122.108.71
e0:f8:47:aa:ba:81
192.168.1.200
32.156.253.20
10:f3:22:a1:b2:c1
192.168.1.1
Test You Network Connectivity
You can test your connection using the PING command. PING is a command line utility that
allows you to send an Internet Control Message Protocol (ICMP) request to another machine
on the network which hopefully then replies. If the output indicates there is no response then
there could be a problem with the network configuration or that the site is not available to
receive PING requests.
To run the PING program from either the Windows or Mac, simply type the ping command and
an IP address or Fully Qualified Domain Name (FQDN). that The format of the PING command
is:
ping remote machines IP address followed by <Enter>.
Therefore to PING www.nba.com, whose address is 216.254.95.72, enter
ping 163.1.2.1 and press <Enter> or ping www.nba.com and press <Enter>
If everything is working correctly you should get the response similar to that shown below:
PING a1570.gd.akamai.net (216.254.95.72): 56 data bytes
64 bytes from 216.254.95.72: icmp_seq=0 ttl=49 time=11.725 ms
64 bytes from 216.254.95.72: icmp_seq=1 ttl=49 time=18.069 ms
64 bytes from 216.254.95.72: icmp_seq=2 ttl=49 time=13.014 ms
64 bytes from 216.254.95.72: icmp_seq=3 ttl=49 time=14.956 ms