TCP/IP (Chapter 6) Flashcards
Simply put, what is a protocol?
A set of rules that govern communications
What is the TCP/IP suite?
Transmission Control Protocol/Internet Protocol
A collection of protocols working together to help computers communicate. It’s named after it’s two hardest-working protocols.
Identify what protocols live where in the DoD model
The botom layer does not contain protocols, but rather methods of accesing the internet.
What protocol is considered the backbone of TCP/IP?
IP
It works in relation to IP addressing. Other protocols in the Internet layer work in conjunction with it.
Where are the majority of TC/IP protocols located?
In the process/application (top) layer
What is the difference between TCP and UDP (Host-to-Host/Transport layer)?
TCP guarantees packet delivery with data acknowledgements (connection-oriented)
UDP does not do this (connectionless), but its somewhat faster
What is the relationship between TCP/UDP (transport layer) and Application layer protocols?
Transport layer protocols (TCP and UDP) help the application layer protocol calls get from point A to point B.
Think of the transport layer protocol as a “carrier” for application layer protocols.
How many total ports are there?
65,536 (starting with 0)
Which ports are considered the well-known ports?
0 through 1023
Which ports are registered ports?
1,024 through 49,151
The rest are freely used by application vendors.
What ports and protocol does FTP use?
20, 21
TCP
–FTP (File Transfer Prot) is responsible for transferring files between a client and a server over a network, allowing users to upload and download files.
What ports and protocol does SSH use?
22
TCP
–SSH (Secure Shell) is responsible for providing a secure, encrypted command-line interface for remote access to a computer over a network.
SS looks like two 2s
What ports and protocol does Telnet use?
23
TCP
–Telnet responsible for providing a command-line interface for remote access to another computer over a network.
Michael Jordan’s jersey, i guess?
What ports and protocol does SMTP use?
25
TCP
–The SMTP (Simple Mail Transfer Protocol) is responsible for sending and relaying outgoing email messages from a sender’s email client to the recipient’s email server.
Sending mail used to cost 25 cents.
What ports/protocols does DNS use?
53
TCP/UDP
–Translates domain names into IP addresses
Do Not eat Salt after 53.
What ports/protocols does DHCP use?
67, 68
UDP
Downtown Has Cheese Pizza where 67th and 68th street cross.
What ports/protocols does TFTP use?
69
UDP
–TFTP (Trivial File Transfer Protocol) is a simplified, connectionless protocol primarily used for transferring files between clients and servers with minimal security and error checking.
Spray and pray!
What ports/protocols does HTTP use?
80
TCP
–HTTP needs to use TCP because it provides reliable, ordered delivery of data, which is essential for ensuring that web pages and other HTTP requests are transmitted accurately and completely across the internet.
What ports/protocols does POP3 use?
110
TCP
–POP3 (Post Office Protocol version 3) used to retrieve email from a remote server
3 numbers, last one p0ps.
What ports/protocols does NetBIOS/NetBT use?
137, 139
TCP
–NetBIOS enables communication between computers on a LAN for file sharing, printer sharing, and name resolution. Heavily used by Microsoft.
Remember that 2-THREE had the NET
What ports/protocols does IMAP4 use?
143
TCP
–IMAP4 is POP3 but more advanced
ONE FOUR is more (advanced) than THREE
What ports/protocols does SNMP use?
161, 162
UDP
–SNMP (Simple Network Management Protocol) is used for monitoring and managing devices on a network.
What ports/protocols does LDAP use?
389
TCP
–LDAP (Lightweight Directory Access Protocol) is used for accessing and managing directory services, including user authentication and account management.
What ports/protocols does HTTPS use?
443
TCP
What ports/protocols does SMB/CIFS use?
445
TCP
–SMB/CIFS (Server Message Block / Common Internet File System) is used for sharing files, printers, and other resources between computers, primarily in Windows environments.
FOR FOUR or FIVE devices to use on the network
What ports/protocols does RDP use?
3389
TCP
–RDP (Remote Desktop Protocol) allows remote access and control of computers or virtual machines over a network.
If you’re going remote, you’ll need to add an extra 3.
What is any device with an IP address called?
A host
What determines where the network ID ends and the host ID begins?
The subnet mask
What is a default gateway?
The IP address of the device that allows the host to connect outside of the local network. This is usually your router.
What are the first octets of a Class A network?
0 - 127
Reserved for very large networks
What are the first octets of a Class C network?
192 - 223
What IP is the loopback address?
127.0.0.1
Used for troubleshooting network adapaters
What is the default subnet mask of a Class C network?
255.255.255.0
Example: 192.168.111.85/24
The first 24 bits (three octets) are the network ID.
What is CIDR?
Classless inter-domain routing
Allows you to not use the default subnet mask. This increases the flexibility in determining how long the network ID is (and thus how many hosts it can have).
What is NAT?
Network Address Translation
It runs on a router and handles the translation of private, nonroutable IP addresses into public IP address.
What are private IPs and what’s significant about them?
They’re used on private networks and are not routable on the Internet. It freed us from the requirement that all address be globally unique.
Recall the private IP address ranges
Recall the DHCP request process
The steps DHCP DISCOVER and DHCP REQUEST from the client to the server are broadcast. What does this mean?
Broadcast means every computer on the network segment receives and needs to process the message. Excessive broadcasts can slow down network performance.
Messages from the DHCP server to the client are unicast
What do APIPA addresses start with?
169.254.x.x
They get this if they are unable to reach a DHCP server.
What is a zone file?
A database in every DNS server which maintains records of hostname to IP address mappings
Recall DNS record types
If a DNS server doesn’t know an IP address and its not in the zone file or cache, what does it do?
It queries the root server
What is ARP and what does it do?
Address Resolution Protocol
Resolves IP addresses to MAC addresses.
Which protocols are responsible for email retrieval and which is for sending?
IMAP4 (secure) and POP3 retrieve
SMTP (mail transfer protocol) sends
Which protocol is for network management?
SNMP
What are the different DNS address classes (found in records in a zone file)?
A (IPv4)
AAAA (IPv6)
MX (mail exchange)
TXT (text)
What is so special about TXT DNS addresses?
They can be used to combat email spam with DKIM, SPF and DMARC
What is the IPv6 loopback address?
::1
What is the IPv6 unicast address range?
2000::/3
What is the different between a VLAN and a VPN?
A VLAN is a logical network configured through a managed switch.
VPNs are a secure point-to-point connection.
Can a DNS server have a public or private IP address?
No. It needs to have a public IP address. Any private address wouldn’t be valid.
Example: 10.25.11.33 is not valid because it’s within the private IP address range.
192.186.12.2 would be valid.
Know private IP address ranges
10.0.0.0 - 10.255.255.255
172.16.0.0 -172.31.255.255
192.168.0.0 - 192.168.255.255
Which of these is a private IP address?
192.168.12.2
192.186.10.3
192.168.12.2
196.86 is outside of the private range.
What are two protocols that allow for private file transfer?
SFTP
FTPS
What is the size of an IPv6 address space?
128 bits