IP Addresses Flashcards
IPv4 Address
The logical address to a computer, consists of 32 bits in length, often represented in decimal format, 192.168.0.1, or in 4 binary octets. An IP address has an IPv4 or IPv6 address, a subnet mask, and a default gateway (aka the destination router)
IP related protocols
TCP Transmission Control Protocol and Internet Protocol IP
Private IP Range
These IP address ranges can be used on multiple networks, ensuring that they are not reachable through the internet.
Class A: 10.0. 0.0 to 10.255. 255.255.
Class B: 172.16. 0.0 to 172.31. 255.255.
Class C: 192.168. 0.0 to 192.168. 255.255
Private IP Address
These IP addresses are normally an IPv4 IP address and are referred to as an RFC1918 IP address. Internal or private IP addresses are not reachable by external devices over the internet
APIPA
Automatic Private IP Addressing, self-assigns an automatic ip address with a specific network ID: 169.254.0.0/16, this happens when no DHCP server is found and the device does not have a static ip address assigned to it
Fail Safe
DHCP
dDynamic Host configuration Protocol. Keeps records of all assigned ip addresses. IP address assignment is automatic, ip addresses are assigned quickly
Static IP Address
Manually set ip address on the computer, then you need to manually keep track of each assigned AP, mostly used on servers/routers/switches where ip addresses should never change
Dynamic IP Address
IP address assignment is automatic, ip addresses are assigned quickly, best for hosts, phones, or other network nodes that don’t need a dedicated ip address. Requires a DHCP server
Minimum Required IP Settings
IP Address, Subnet Mask, Defauylt Gateway, DNS (can function without DNS but would not be able to browse the web)
Zero-Config Networking
Goal is to allow computer sand networking peripherals to be locally networked without manual configurations or special services.
Parts:
1. Automatic Link-local address assignmnets (APIPA)
2. Automatic hostname resolution (multicast DNS, NetBios)
3. Automatic Network Service location (printing, etc.)
Fail Safe
IPv4 Class system
IP classes provide a default mask based on the number in the first octet. Before subnetting existed:
Class A: 1st Octet Range: 1-126 Subnet: 255.0.0.0
Class B: 1st Octet Range: 128-191 Subnet: 255.255.0.0
Class C: 1st Octet Range: 192-223 Subnet: 255.255.255.0
Loopback Address
Any ip address that contains 172 in the first octet, 127.0.0.0/8 so 127.0.0.1-127.255.255.254
Link-Local Address
APIPA address, 169.254.0.0/16
CIDR Notation
Tells you how many binary bits are turned on in the subnet mask
EX: 192.168.1.0/24 = 11111111.11111111.11111111.00000000 = 255.255.255.0
Usable IP Address Range
For subnetting to determine the usable ip range on a subnet
EX: 192.168.50.1 - 192.168.50.230
Broadcast Address
The ip address that will reach out to all the clients on the network for updates, information, etc. Always one less than the next subnet in the network
Bit Identification Technique
Given the network ID, Subnet Mask, and CIDR notation we can determine the broadcast address and the useable ip address range
IPV6
IPv6 Address is a 128 bit address represented as 32 hex digits, composed of 8 groups of 4 hex digits
Ex: 2001:0db8:85a3:0000:118d:8a2e:0370:7334
Dropping leading zeros, and groups of 4 zeros we get:
2001:db8:85a3:0:118d:8a2e:370.7334
If there are contiguous groups of zeros they can be replaced with a double colon
Ex: 2001:0db8:85a3:0000:0000:8a2e:0370:7334 becomes 2001:db8:85a3::8a2e:370:7334
Ipv6 is needed as the number of available addresses for IPv4 are running out
IPv6 Loopback
0000:0000:0000:0000:0000:0000:0001
We can abbreviate with colons to leading zeros, and to simply colons if there are contiguous groups of zeros:
0:0:0:0:0:0:0:0:1
::1
IPv6 Internet access
Ipv6 address needs both a link local and global ip address to connect to the intenet
IPv6 Address Types
IPv6 addresses need a global address, a link local address and a unique local address. Can be automatically configured or manually configured
IPv6 Link Local Address
Always starts with FE80::/64
IPv6 Subnet mask
Always /64
IPv6 Bits
First 64 bits represent the network and the last 64 bits represent the host
Public IP Address
Public ip addresses are used on the internet. You just have one public IP address and it’s assigned to your gateway or router, so as not to expose your computer to the internet directly
Datagram
The combination of an IP address and UDP (User datagram protocol)
No assurance datagram will be received
Connection-less
Contains a source port, destination port, length, checksum, data (if any).
Packet
The combination of an IP address and TCP (Transmission Control Protocol)
Devices are talking to each other to ensure packet delivery
Connection Oriented
Always contained within a frame
Data –> Packet –> Frame
Data gets turned into a packet and then is absorbed in a frame and then sent on the wire
UDP
User Datagram Protocol
Unreliable delivery, not ordered, no congestion control, light weight, faster than TCP, connection-less.
IP
Internet Protocol provides logical addressing for networks
Frame
Encapsulates data to send along the wire.
Frame has, starting at the front:
MAC Header
IP Header
TCP/UDP Header
Data
CRC
TCP
Transmission Control Protocol - data unit is called a segment. Reliable communication, favors safety over speed, Connection oriented, sequence # and acknowledgement # to keep track of data.
Ordered, stream of segments
Error detection and correction
Flow control
Congestion control
Complex and Heavyweight
TCP Three-way Handshake
Messages sent between computers to ensure the data is delivered.
Session Establishment:
First, a SYN is sent from source to destination
Second, a SYN ACK is sent from destination to source
Third, ACK sent to destination computer to establish session
Session Termination:
First, source sends a FIN to the destination
Second, the destination sends an ACK to the source
Third, the Destination sends a FIN ACK to the source
Fourth, the source sends an ACK to the destination to terminate the session
