Chapter 7 - TCP/IP Basics Flashcards
Define Protocol Suite
a set of rules for developers/manufacturers to follow
Define Protocol Stack
Software on a system that enables a specific protocol suite to function
Define Internet Control Message Protocol and its purpose.
Features are called automatically by applications as needed without the user knowing. i.e. Ping utility used ICMP.
How many fields does a full IP packet have
14
How is a simple IP header constructed
Ver - defines IP address; 4/IPV4, 6/IPV6
Header length: size of IP portion (32 bits)
DSCP - Differentiated services code point; contains data for bandwidth sensitive application; type of service
TTL - Time to Live; max 255, avg 128; counts each loop through the router
TCP/UDP - identifies what is inside.
What does TCP require
Process of ACK/NACK Both the sending & receiving machine need to acknowledge each others presence and readiness to send and receive data. Also chops data into segments
How does a client know where to return the data
The client remembers the source port number to assign it to the proper application
Give example of a TCP/UDP header
Source Port
Destination Port
Sequence Number
ACK
What is the purpose of the Sequence/ACK numbers
To keep track of various pieces of data moving in and out
Why do we use flags
Give individual bits detailed information about the connection
Why do we use a checksum
checks the TCP header for errors
What are two important protocols that use UDP
Domain Name System
Dynamic Host Configuration Protocol (DHCP)
Describe a UDP header
Source Port
Destination Port
Length
checksum`
Where does TCP chop up the data
Transport Layer; UDP only gets a header at this stage
What does a computer interpret a IP address as
32 Bit binary address
What is another name for a router
Default Gateway
Why do we use network IDs
to connect to multiple LANs
What is required when sending data to another computer
MAC address
What is a subnet mask
a string of ones and zeroes always totalling 32 bits
How do you pick out the host ID in a subnet mask
Line up a IP address and a subnet mask. The portion that aligns with the ones of the Subnet mask is the network ID.
- 168.5.23 -> 11000000.10101000.00000101.00010111
- 255.255.0 -> 11111111.11111111.11111111.00000000
Network: 11000000.10101000.00000101.x
Host: x.x.x.00010111
What is the first step to sending data out
The computer compares the destination IP to its own address using the subnet mask.
Define Address Resolution Protocol (ARP)
How a TCP/IP network figures out the MAC address based on the destination IP address
What does an ARP frame look like
Hardware type Protocol type Hardware length Protocol length Operatjon Sender hardware address Sender protocol address Target hardware address Target protocol address
How is the shorthand of a MAC address used
Using a /# (i.e. /24) to indicate the number of ones.
What purpose does IANA have
Formed to track and disperse IP addresses to those who need them. They hand out contiguous chunks called network blocks
What is the range of a Class A address
1.0.0.0 - > 126.255.255.255
16,277,214 Hosts / ID
What is the range of a Class B address
128.0.0.0 - > 191.255.255.255
64, 534 Hosts / ID
What is the range of a Class C address
192.0.0.0 - > 223.255.255.255
254 Hosts / ID
What is the range of a Class D address
224.0.0.0 - > 239.255.255.255
Multicast
What is the range of a Class E address
240.0.0.0 - > 254.255.255.255
Experimental
What are the three ways to send a packet
Broadcast: every computer hears
Unicast: one to one
Multicast: sends to a group
What is the difference between subnetting and CIDR
Subnetting breaks a single block of addresses into multiple subnets
CIDR takes a block of IP addresses and passes them out
What are two important things to remember about subnetting
Start with the given subnet mask and move to the right until you have the correct number of subnets
Forget the dots, they don’t mean anything to the computer
How do you calculate the number of hosts in a subnet mask
2^x - 2
x= number of zeroes
Outline the process of Subnetting
OG subnet: 111111111111111111111111 | 00000000
Network extension: 111111111111111111111111 | 0 | 0000000
New sub net 111111111111111111111111 | 10000000
= 255.255.255.128
Outline the process of making 3 new subnets
Translate subnet mask into 3 new subnets
11000000.10101000.00000100.00000000
110000001010100000000100 | 00 | 000000
110000001010100000000100 | 00 | 000001 (host)
110000001010100000000100 | 00 | 000010 (host)
110000001010100000000100 | 01 | 000000
110000001010100000000100 | 01 | 000001 (host)
110000001010100000000100 | 01 | 000010 (host)
110000001010100000000100 | 10 | 000000
110000001010100000000100 | 10 | 000001 (host)
110000001010100000000100 | 10 | 000010 (host)
110000001010100000000100 | 11 |000000
110000001010100000000100 | 11 | 000001 (host)
110000001010100000000100 | 11 | 000010 (host)
Converted back to dot-dec
- 168.4.0 /26
- 168.4.64 /26
- 168.4.128 /26
- 168.4.192 /26
How do you calculate a 8 bit binary value to a number
128 64 32 16 8 4 2 1
1 0 0 1 0 1 1 0
—————————— Add the ones
128 + 16 + 4 + 2 = 150
What ports does DCHP use
67 & 68
What IP address should you tell you there is an error
169.254.0.0 (network ID)
Generated by a version of Zero-config networking (APIPA)
What is the loopback address
127.0.0.1
What are considered to be private IP addresses
- 0.0.0 - > 10.255.255.255
- 16.0.0 -> 172.31.255.255.255
- 168.0.0 -> 192.168.255.255
