Networking for Home and Small Businesses – Chapter 5 Network Addressing Networking for Home and Small Businesses – Chapter 5

Purpose of an IP Address A logical network address that identifies a host A host (end-user) must have a NIC card workstations servers printers router interface Each packet will contain a source and destination IP address Packet Tracer Activity 5.1.1 – Section 2

IP addresses 32 binary digits 4 octets Dotted decimal notation IP Version 4 most common form of IP addresses Over 4 billion possible IP addresses

Binary Numbers The IP address is made up of binary numbers (1 or 0) Humans must be able to talk computer language to send data We do this by converting our numbering system (Base 10 to binary) Let’s try some . . . Convert 140 to binary Convert 10 to binary Convert 11010111 to Base 10 Convert 11111110 to Base 10 Time to play a game -- Online Activity 5.1.2 – Section 3

Parts of an IP Address Hierarchial Similar to your phone number made up of 2 parts network host determined by IP class Similar to your phone number Area code = network phone number = host

Purpose of the Subnet Mask Helps identify network bits (all 1s) and host bits Boolean math or “ANDING” What happens if both source and destination IP are on the same network??

Types of IP Addresses Class A Range 1-127 N.H.H.H First bit in octet will be a 0 Default subnet mask 255.0.0.0 can create over 16 million host addresses 224 – 2 = 16,777,214 to be exact why do you subtract 2??? Used in large organizations

Types of IP Addresses Class B Range 128-191 N.N.H.H First bit in octet will be a 1 Default subnet mask 255.255.0.0 can create over 65,000 host addresses 216 – 2 = 65,534 to be exact Used in medium-sized organizations

Types of IP Addresses Class C Range 192 -223 N.N.N.H First two bits in octet will be a 11 Default subnet mask 255.255.255.0 can create 254 hosts 28 – 2 = 254 to be exact Used in small organizations

Types of IP Addresses Class D Class E Range 224 - 239 used for multicasting not for commercial use Class E Range 240 - 255 reserved for experimental use

Private IP Addresses Helps avoid the problem of limited IP addresses Allows hosts to communicate locally without each device needing a public IP address Not routed on the Internet; blocked by the ISP router Private address ranges assigned by RFC 1918 Request for comment all classes can be used for any size network most use Class A

Unicast Address Most common type of address Intended for a specific host Must have both destination IP and MAC in the header

Broadcast Address All ones in the host portion of the IP address Class C address: 204.33.4.0 (N.N.N.H) Broadcast address: 204.33.4.255 MAC address all Fs FF-FF-FF-FF-FF-FF

Multicast Address Send packet to a group of devices Must use multicast address range Range 224.0.0.0 – 239.255.255.255 Used for remote gaming MAC address begins with: 01-00-5E

Using Static IP Addressing Manually configured by the network administrator Advantages useful for printers, servers, etc increased control of resources (security) Disadvantages time consuming

Using Dynamic IP Addressing Automatic assignment of IP addresses Useful if frequent change in users (wireless hotspot) Uses DHCP (Dynamic Host Configuration Protocol) server IP addresses leased for a period of time if host is removed from the network (turned off), the IP address goes back into the pool of IP address Preferred method for large networks reduces the burden of network support

Configuring DHCP If host is configured as DHCP client, it will not have a IP address Subnet Mask Default Gateway Clients send a DHCP address Broadcast IP and MAC only DHCP server replies Server responds with DHCP offer of an IP address Host/client sends DHCP request asking server to use the IP address Server responds with DHCP acknowledgment

Obtaining an IP address from DHCP server Multifunction device (Linksys Router) provides services to clients (SOHO network) Configuring the DHCP server Enter router default IP address and subnet mask for internal interface IP = 192.168.1.1 Subnet Mask = 255.255.255.0 On DHCP screen check range number of users lease time (24 hours by default)

Purpose of a Gateway Used by the router to provide the path through which hosts on one network can communicate with hosts on a different network Default gateway address IP address of the router interface If DHCP is being used the DHCP server will automatically send the correct IP interface to the host to use as the default gateway

Address Assignment ISR (Integrated Services Router) Default IP address Class C Private Address Configured on router interface Internal hosts must be assigned addresses within the same network

Address Management Direct Connection direct connection from PC to ISP through modem public address assigned to the host Connection through Integrated Router more than one host needs access to the Internet modem connected to ISR Connection through Gateway Device ISR and modem in one unit connect directly to ISP

Using NAT with a Home or Small Business Network NAT (Network Address Translation) Translates private IP addresses into unique public address for Internet communication Only packets destined for different network use NAT