Section 7: IP Addressing Flashcards
Class A Address Range / Classful Subnet
1 - 127 / 255.0.0.0 (16.7 million possible hosts)
Class B Address Range / Classful Subnet
128 - 191 / 255.255.0 .0 (65,536 possible hosts)
Class C Address Range / Classful Subnet
192 - 223 / 255.255.255.0 (256 possible hosts)
Class D Address Range / Classful Subnet
224 - 239 / (NA) (Reserved for Multicast Routing)
Class E Address Range / Classful Subnet
240 - 255 / (NA) (268 million possible hosts; Reserved Range for research and development)
CIDR
Classless Inter-domain Routing - Borrowing some host bits and reassigning them to the network portion.
Class A CIDR notation
IP address / 8 (Meaning 255.0.0.0 subnet mask with 8 1’s and 24 0’s)
Class B CIDR notation
IP address / 16 (Meaning 255.255.0.0 subnet mask with 16 1’s and 16 0’s)
Class C CIDR notation
IP address / 24 (Meaning 255.255.255.0 subnet mask with 24 1’s and 8 bits of 0’s)
Routable (Public IP Addresses)
Directly accessible over the internet and assigned by an ISP
Non-Routable (Private IP Address Ranges)
RFC 1918 - Only usable within a LAN
▪ Class A - Any address starting with 10
10.0.0.0 - 10.255.255.255 (256x256x256=16.7 million hosts)
▪ Class B - 172.16 - 172.31
172.16.0.0 - 172.31.255.255 (16x256x256=1.05 million hosts)
▪ Class C - 192.168
192.168.0.0 - 192.168.255.255 (256x256=65,536 hosts) (Anything starting with a 192.168)
Loopback Address (or Local Host)
127.0.0.1 / 8 - Loopback to the host and generally used for testing protocols. (The entire 16.7 million address range)
APIPA / Range
Automatic Private IP Address
Class B: 169.254.0.0 to 169.254.255.255 / 255.255.0.0
- Default address when a network device does not have a static address or cannot reach a DHCP server. (Dynamically assigned by host.)
DORA Process
Discover; Offer; Request; Acknowledge
(Used by DHCP to provide IP addresses to hosts/client machines)
Virtual IP Address
VIP or VIPA - Adress does not correlate to actual physical network interface. Gives one interface multiple IP Addresses. Used for NAT, Fault-tolerance and virtualization.
Sub-interfaces
Virtual interface created by dividing one physical interface into multiple logical interfaces.
Unicast
Data travels from a single source to a single destination device.
Multicast
Data travels from a single source to multiple, but specific, destination devices.
Broadcast
Data travels from a single source to all devices on a destination network.
Static IP Assignment
Manual IP address assignment.
(Impractical on large networks.)
Dynamic IP Assignment
Dynamic allocation of IP addresses.
Four IP Components for a fully configured network client.
IP Address;
Subnet Mask;
Default Gateway Address;
DNS/WINS Server Address (WINS is optional and may not be sent)
DNS - What it does.
Domain Name System - Converts domain name to IP address.
WINS - What it does.
Windows Internet Name Service - Used within a Windows network and converts NetBIOS names to IP addresses.
Four ways to dynamically assign IP addresses
BootP
- Bootstrap - Oldest and least used method. Originally developed for use with diskless workstations.
DHCP
- Replaced BootP - Assign IP information based on scope / pool of addresses.
APIPA
- Assigned by Operating System when a device does not have static address or cannot reach DHCP server. Not routable because no default gateway defined.
ZeroConf (Zero Configuration)
- Newer technology based on APIPA. Able to resolve computer names via mDNS (Multicast DNS); can perform service discovery. (Known as Bonjour for Apple products; LLMNR - Link-Local Multicast Name Resolution for Windows environments; SystemD for Linux systems.)
Class A Classful: Dotted Decimal Subnet / Prefix Notation
255.0.0.0 / 8
Class B Classful: Dotted Decimal Subnet / Prefix Notation
255.255.0.0 / 16
Class C Classful: Dotted Decimal Subnet / Prefix Notation
255.255.255.0 / 24
Class D Classful: Dotted Decimal Subnet / Prefix Notation
na / na
Loopback Addresses Block
127.0.0.0 / 8 [127.0.0.1 thru 127.255.255.254]
Class A Private Addresses / Subnet Mask
10.0.0.0 - 10.255.255.255 / 255.0.0.0
Class B Private Addresses / Subnet Mask
172.16.0.0 - 172.31.255.255 / 255.255.0.0
Class C Private Addresses / Subnet Mask
192.168.0.0 - 192.168.255.255 / 255.255.255.0
ZeroConf Networking
Zero Configuration Networking
▪ A set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manual operator intervention or special configuration servers.
IPv6 Address Length
128 bits represented by 32 hexadecimal values. (Eight Segments of four Hexadecimal values separated by a single colon.)
IPv6 Address Shorthand
▪Groups of four 0’s can be represented by a single 0.
▪Consecutive groups of 0’s can be represented by a double colon (::) but only once per address.
▪2018:0000:0000:0000:0000:0000:4815:54ae
is equivalent to
▪2018:0:0:0:0:0:4815:54ae
or
▪2018::4815:54ae
Unicast IPv6 Address type
Identify a single interface with
Globally-Routed Addresses - Begins with an address in the range of 2000 - 3999
and
Link-Local (or Local Use) Addresses can only be used on LAN (not routable) and begins with FE80. On startup a Link-Local address is automatically established (even if a static or dynamic host address is configured). This is done using SLAAC (Stateless Address Autoconfiguration) protocol.
Multicast IPv6 Address type
Identifies a set of interfaces and begins with FF.
Anycast IPv6 Address type
Identifies a set of interfaces so that a packet can be sent to any member of the set. No easy way to identify.
