Natalie DeKoker, Lindsay Haley, Jordan Lunda, and Matthew Ott

• A number assigned to each computer or device connected to a network using the internet.

• They are displayed as binary numbers • Dispersed by the Internet Assigned Numbers Authority (IANA)

Data Packet 192.168.1.1

192.168.1.2

• Using example

slide

192.168.1.0

• •

Host ID = last 8 (down to 2) numbers Network ID = first 24 (up to 30) numbers of

• • • •

11000000.10101000.00000001.

000000 00 (192.168.1.0) 11000000.10101000.00000001.

000000 01 (192.168.1.1) 11000000.10101000.00000001.

000000 10 (192.168.1.2) 11000000.10101000.00000001.000000 11 (192.168.1.3)

• Default Gateway and Routing Table

• Allows a computer to tell if the receiving computer is on the same LAN • Always 32 bits – a decimal every 8 bits (octets)

From: To: Subnet Mask: 00010101 .01000000

.01101001

.00000001

00010101 .01000000

.01101001

.00000010

11111111 .11111111

.11111111

.00000000

(21.64.105.1) (21.64.105.2) (255.255.255.0) If Logical AND operation is true, then we are on the same LAN!

11111111.00000000.00000000.00000000 = /8 (Class A) 11111111.11111111.00000000.00000000 = /16 (Class B) 11111111.11111111.11111111.00000000 = /24 (Class C) 11111111.11111111.11111111.11000000 = /26

Calculate Number of Subnets 2^ (number of network ID extension digits) – 2 = number of new subnets Modify Subnet Mask 11111111.11111111.11111111.0000000

 11111111.11111111.11111111.

11 00000 • • •

Host ID = usually last 8 numbers Network ID = usually first 24 numbers of

11000000.10101000.00000001.

01 000000 (192.168.1.64) 11000000.10101000.00000001.

10 000000 (192.168.1.128)

Calculating Hosts From number of zeroes in binary address of the subnet mask, we get: 2 (number of zeroes) – 2 = number of possible hosts Note: The more subnets we make, the less hosts we can have per subnet!

CIDR = Classless Inter-Domain Routing This is how ISP’s allot their IP addresses.

• Allows host to communicate with other hosts when only the neighbor address is known • Host requests own IP address via network • Host sends hardware address (MAC) • Network assign IP address 192.168.0.1

2e:3d:6c:4f:b2:15

• • Network automatically assigns IP address DHCP Anyone out there?

Can I have an IP address?

This address will expire in 7 days.

• APIPA Anyone out there?

Can I have an IP address?

Ok, I’ll assign myself 169.254.0.3 for now, and I’ll check back later.

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