Network Protocols Flashcards
Convert to Binary Octet = 234
11101010
Convert to Binary Octet = 168
10101000
Convert to Binary Octet = 99
01100011
Convert to Binary Octet = 25
00011001
Convert to Binary Octet = 189
10111101
Convert to Digital = 01010101
85
Convert to Digital = 10011111
159
Convert to Digital = 00111001
57
Convert to Digital = 10011100
156
Convert to Digital = 11011001
217
How does the network ID in an IP address relate to the host ID?
The network ID on the left identifies the subnet the host belongs to, and the host ID on the right identifies its place on that subnet. Each can vary in length, but the two together are always 32 bits.
How can classful addresses be used in a classless address system?
CIDR is backwards-compatible. Existing class A, B, and C addresses just have subnet prefixes of /8, /16, and /24 respectively.
What can you tell about this address: 10.124.1.92
It’s a private network address, routable within an organization but not on the Internet.
What can you tell about this address: 127.0.0.1
It’s a loopback address: packets sent there just return to the local host.
What can you tell about this address: 169.254.1.13
It’s a self-assigned address, which works on the local segment but can’t be routed.
What can you tell about this subnet mask: 255.0.255.0
It’s not a valid subnet mask since it doesn’t have contiguous 1s followed by contiguous 0s. The host is improperly configured.
Loopback IPv6
::1/128 returns to the same interface. Equivalent to 127.0.0.1/8 in IPv4.
Link-local IPv6
Usable on the local segment, but not routable.
Unique local IPv6
Routable within a private network, such as one managed by a single organization or group of organizations, but not on the public internet.
Global IPv6
Routable on public networks such as the Internet
Why is IPv6 being adopted?
The most pressing reason is the depletion of available IPv4 addresses, but it also makes network configuration easier, routing more efficient, and security stronger.
What address scopes can an IPv6 unicast address have?
From smallest to largest: loopback, link-local, unique local, and global.
What IPv6 address would take the place of 127.0.0.1?
::1/128 is the IPv6 loopback address.
What can you tell about this IPv6 address: fe80::c2ad:5783:91:12c2
It’s a link-local address, self-assigned and only usable on the local network segment.
What can you tell about this IPv6 address: fd00:34a0:90d::3001:a0a7
It’s a unique-local address, routable within the organization but not on the internet.
What can you tell about this IPv6 address: 2001:d18:c34d:0:0:0:0:300
It’s a public unicast address, routable on the internet.
Your company has two sites, each with its own LAN: both are IPv6 ready, but the WAN link between the two is still IPv4. How can you reach other company servers?
You can use IPv6 addresses for hosts on your own LAN. To contact the other site you’ll need an IPv4 address unless there’s a tunneling setup.
Top-Level Domain (TLD)
The root category of the domain. Originally these were either three-letter functional categories like .com or .edu, or two letter country codes like .uk or .jp.
Domain
Represents a particular organization. Domain names are registered, or rented, from a registrar: each TLD registrar can set its own fees and eligibility requirements.
Subdomain
An optional level used for categories within the organization. The organization can allocate and use subdomains as it sees fit.
Hostname
he name of the specific host within the organization, or its alias.
Local host mocha wants to send a packet to remote host kona on its subnet. It knows kona’s address is 192.168.100.20. Describe the address resolution process mocha needs to follow.
mocha first will look in its ARP cache to see if it has kona’s MAC address. If not, it will use an ARP request using kona’s IP address to find its MAC address. Afterward, both hosts add each other to their ARP caches.
What does each segment of the FQDN mocha.corporate.javatucana.coffee represents, and who assigned it?
mocha is the host name, and corporate a subdomain: both can be assigned internally by the company. javatucana is a domain name, and was registered with and aapproved by a public domain registry. .coffee is a top level domain, which was approved by the IANA.
You want to connect to mocha.corporate.javatucana.coffee over the Internet. Describe the address resolution process your computer needs to follow
Your computer will first look for mocha’s IP address in its DNS cache. Assuming it isn’t, it will send a DNS request to its DNS server. The server will check its own address records, and consult higher level servers if necessary. Finally, it will send mocha’s IP address to your computer, which will make the connection using the default route. Finally, your computer will add mocha to its DNS cache.
Static Assignment
Manual assignment of address settings on the host itself
Dynamic Assignment
Automatic assignment of an address by a server on the local network.
Stateless Address Configuration
A private IP address chosen by the host itself through communication on its local subnet. This method produces private, non-routable addresses, so it’s only useful for local communications.
APIPA
Automatic Private IP Addressing
ARP
Address Resolution Protocol
NDP
Neighbour Discovery Protocol
CIDR
Classless Interdomain Routing
RIR
Regional Internet Registry
IANA
Internet Assigned Numbers Authority
What are the 2 types of DHCP?
DHCPv4 for IPv4 and DHCPv6 for IPv6
EIGRP
Enhanced Interior Gateway Routing Protocol
OSPF
Open Shortest Path First
RIP version 2
Routing Information Protocol Version 2
What are the Private 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
IP range for Class A private address?
10.0.0.0-10.255.255.255
IP range for Class B private address?
172.16.0.0-172.31.255.255
IP range for Class C private address?
192.168.0.0-192.168.255.255
If windows cannot obtain an IP address, it will automatically assign one. How does the beginning of this IP address always start?
169.254
How does a link-local address start on IPv6?
fe80
What problems might you see if a host was configured to use DHCP on a network without a valid DHCP server?
An APIPA or link-local address, and an inability to communicate with hosts outside the local network segment.
What problems might you see from an invalid or duplicate IP address?
Inability to reach any hosts, or unpredictable connectivity.
What problems might you see from invalid DNS settings?
Inability to reach hosts by name, even when they’re reachable by IP address.
Can you assign a static IP address while relying on an automatic DNS server assignment?
Not for IPv4; you will need to assign a DNS server manually too. IPv6 allows automatic DNS discovery without DHCP, but only if a local router is providing DNS advertisements.
Which protocol is used to find the MAC address of a given IP address?
ARP
List 3 valid subnet masks?
- 0.0.0
- 255.0.0
- 255.255.0
What is the range of a site local IPv6 address?
fec0-fef0
What is the range of a global IPv6 address?
2000-3fff
What is TCP?
Transmission Control Protocol
What is UDP?
User Datagram Protocol
Name 5 Benefits of TCP?
Connection Orientated - Reliable - Error Correction - Flow Control - Sequencing
What features separate TCP from UDP?
TCP is connection-oriented and reliable, while UDP is connectionless and unreliable. TCP has segments, UDP has datagrams. TCP has error correction, sequencing, and flow control, while UDP only has basic error correction via a checksum.
Why would an application use UDP rather than TCP?
It’s faster and more efficient, so it’s good when speed matters more than accuracy, when only short messages are being sent, or when the application layer is handling error correction and sequencing.
What are System Ports?
Ports 0-1023 are assigned to the most universal and accepted TCP/IP standard applications, or applications the IANA expects to become standards.
What are User Ports?
Ports 1024-49151 are assigned to applications that benefit from assigned port numbers, but aren’t so widely used that they need to become a worldwide standard.
What are Private Ports?
Ports 49152-65535 aren’t assigned by the IANA, and can be used for any purpose without registration.
HTTP
Hypertext Transfer Protocol - Used to retrieve data from web servers - Port 80
HTTPS
HTTP over TLS/SSL - Used for secure web pages and sites. included encryption services. - Port 443
FTP
File Transfer Protocol - Used for transferring files between hosts. Contains basic authentication features - Port 20 (data) + port 21 (control)
Telnet
Used to log into remote systems via a virtual text terminal interface - Port 23
SSH
Secure Shell - Encrypted replacement for Telnet and FTP. Includes Secure Copy Protocol (SCP) and Secure Shell FTP (SFTP) - Port 22
SMTP
Simple Mail Transfer Protocol - Sends email to and between mail servers - Port 25
POP3
Post Office Protocol Version 3 - Retrieves email from mail servers - Port 110
IMAP
Internet Message Access Protocol - Retrieves email from mail servers - Port 143
SMB
Server Message Block - Used to share files and resources like printers - Port 445
AFP
Apple Filing Protocol - Used to share files on OSX and MacOS networks - Port 548 or 427
SLP
Service Location Pprotocol - Allows computers to find network services without prior configuration. Most commonly used for network printers. - Port 427
LDAP
Lightweight Directory Access Protocol - Used for network directory services that centrally manage user accounts and network services. - Port 389 + Port 636 (Secure)
RDP
Remote Desktop Protocol - Used for remote logins to Windows systems. - Port 3389
NetBIOS
Network Basic Input/Output System - Provides name, datagram, and session services for networks using the NetBIOS API. NetBIOS used on TCP/IP networks is sometimes called NetBT. SMB often uses NetBIOS functions as well. - Port 137 + Port 139
SNMP
Simple Network Management Protocol - Used to remotely manage and monitor network devices. - Port 161 + Port 162
Syslog
Sends system status messages to a central server for monitoring and review. - Port 514
DNS
Domain Name System - Resolves domain names into IP addresses. - Port 53
DHCP
Dynamic Host Configuration Protocol - Dynamically assigns IP addresses and other network configuration on joining a network. - Port 67 + Port 68
What port on your computer does your web browser use?
The source port is from the dynamic port range allocated by the operating system. HTTP uses port 80, but that’s on the remote web server.
How do system ports differ from user ports?
System ports are only assigned to important or standardized services, and some operating systems only let services with administrative privileges to bind to these ports. User ports can be registered by any valid application creator, and user applications can bind to them.
What protocol is used to remotely manage and monitor network devices?
SNMP
Which of the following protocols sends system status messages to a central server for monitoring and review?
Syslog
Which port is important for sending an email?
Port 25
TCP contains a checksum which is used for error detection. True or False?
True
TCP is faster and efficient, when speed matters more than accuracy or when only short messages are being sent. True or False?
False
TCP guarantees that all data is successfully delivered to the host. True or False?
True
TCP sends datagrams without setting up a connection or waiting for an acknowledgment. True or False?
False
TCP guarantees that the broken segments will be delivered to the upper layers in the correct sequence. True or False?
True
Authentication Server
Controls access to the network and other resources.
DHCP Server
Provides dynamic IP address configuration to client systems
DNS Server
Provides domain names lookups for client systems
Endpoint Management Server
Manages security policies for end user systems such as PCs and mobile devices. An endpoint management server may centrally administer antivirus protection, security logging, and policy compliance enforcement across the entire network.
File Server
Provides centralized file storage and sharing for network users.
Mail Server
Receives, stores, and delivers email messages.
Print Server
Provides central access to a network printer. Today, network enabled printers usually run print server applications and connect directly to the network.
Proxy Server
Relays communications between LAN hosts and internet hosts. A proxy server may be used for some protocols or all communications; depending on the network it might be designed to improve security or performance.
Syslog Server
Gathers syslog data from other computers and devices on the network and compiles them into one place. A syslog server commonly includes features that process raw logs then generate reports or alerts which are more useful to human administrators.
Web Server
Distributes web pages. Internet web servers might be most familiar, but local network applications often use web servers as well, even an embedded appliance like a home router or network printer will typically use a web server for its configuration interface.
Remote access protocol: Telnet
Allows a command line terminal interface with a remote system.
Remote access protocol: SSH
Secure shell was developed as a secure alternative to Telnet: it allows stronger authentication and encrypted transmission.
Remote access protocol: RDP
Remote Desktop Protocol is Microsoft’s proprietary remote access protocol.
Remote access protocol: VNC
Virtual Network Computing is an open set of standards based on the Remote Frame Buffer (RFB) protocol.
Remote access protocol: HTTP
Web-based interfaces aren’t that suitable for remote access to a graphic or command-line shell interface, though it’s possible with the assistance of a web-based application.
Remote access protocol: SNMP
Simple Network Management Protocol is used to remotely manage and monitor network devices like routers and switches.
RFB Protocol
Remote Frame Buffer
Authentication Systems: RADIUS
Remote Authentication Dial-In User Service authenticates users when they attempt to connect to the network.
Authentication Systems: TACACS+
Terminal Access Controller Access-Control System Plus is a proprietary Cisco protocol with similar functions to RADIUS.
Authentication Systems: Kerberos
Allows a client to access multiple network resources via a single sign-in.
Authentication Systems: 802.1X
An IEEE standard used to authenticate connections to an ethernet switch or wireless access point.
Authentication Systems: LDAP
Lightweight Directory Access Protocol manages distributed directory information services across a network.
Resource Sharing Protocols: FTP
One of the oldest Internet protocols, File Transfer Protocol allows network access to files.
Resource Sharing Protocols:SMB
Server Message Block allows folders or hard drives to be shared over the network and accessed much like they were local drives.
Resource Sharing Protocols: AFP
Apple Filing Protocol operates similarly to SMB, but with specific features more tuned to Apple’s file systems.
Resource Sharing Protocols: NetBIOS
A session-layer API, rather than strictly a protocol, NetBIOS is designed to allow various applications to communicate over the network.
What kind of server is used to relay communications between LAN hosts and Internet hosts?
A Proxy Server
Name a communication protocol for electronic mail transmission?
SMTP, IMAP, MAPI, POP3 etc.
What protocol is used to share files and resources?
SMB
HTTPS uses port 443 for accessing any web-based sensitive information over the Internet. True or False?
True
Which of the following addresses is equivalent to fe80:0000:0000:0000:c249:3765:00c0:9b22?
fe80::c249:3765:c0:9b22
Which resource sharing protocol allows folders or hard drives to be shared over a network?
SMB
Which protocol is used to remotely manage and monitor network devices like routers and switches?
SNMP
Which protocol is designed to provide strong authentication for client/server applications by using secret-key cryptography?
Kerberos
Which of the following ports is used by the Server Message Block (SMB) protocol?
445
What is the subnet mask of the address 144.201.5.32?
255.255.0.0
Which is an Internet service that translates domain names into IP addresses?
DNS
Which IPv4 address range is reserved for APIPA?
169.254.0.0/16
Which protocol is used to retrieve email from mail servers?
IMAP
Which of the following is a non-routable address?
0.0.0.0
Which of the following WPA options is also known as 802.1x mode?
WPA-Enterprise
Which of the following WPA options is also called pre-shared key (PSK)?
WPA-Personal
Which Wi-Fi standard supports speeds up to 54 Mbps over the 2.4 GHz band?
802.11g
Which technology uses a variety of ISM bands, with 2.4 GHz and 915 MHz bands being the most common?
ZigBee
Which technology supports throughput up to 40 kbps over distances of 10-100 m?
Z-Wave
Which wireless technology allows identification and communication between nodes using electromagnetic fields?
Radio frequency identification
Which Wi-Fi encryption standard encrypts traffic using Temporal Key Integrity Protocol (TKIP)?
WPA
