Networking Domain Flashcards
I: LAYER 2
Layer 2 (data link layer) the protocol you’re likely most familiar with is Ethernet. Devices in an Ethernet network are identified by a MAC (media access control) address, which is generally hardcoded to a particular device and doesn’t normally change.
I: LAYER 4
Layer 4 (transport layer) deals with the coordination of the data transfer between end systems and hosts. The best-known example of the Transport Layer is the Transmission Control Protocol (TCP), which is built on top of the Internet Protocol (IP), commonly known as TCP/IP.
I: DNS
DNS is the phonebook of the Internet. Humans access information online through domain names. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.
I: WWW.DOMAIN.COM
- DNS lookup to find the IP address of the server
- Browser initiates a TCP connection with the server
- Browser sends an HTTP request to the server
- Server handles the incoming request
- Browser receives the HTTP response
- Browser displays the html content
- Client interaction with server
I: TCP CONNECTION
To establish a connection, the three-way (or 3-step) handshake occurs:
SYN
SYN-ACK
ACK
I: VLANs
is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2).
I: BGP
BGP (Border Gateway Protocol) are the core routing protocol of the internet and responsible to maintain a table of Internet protocol networks.
I: SWITCH
Switch facilitates the sharing of resources by connecting all the devices, including computers, printers, and servers, in a network.
I: MPLS
is a protocol-agnostic routing technique designed to speed up and shape traffic flows across enterprise-wide area and service provider networks.
Layer 2 point to point – is a cost effective and flexible alternative to high bandwidth leased lines.
Layer 3 IP/VPN – suitable for large multi-site enterprise, i.e. retail chains, which deploy a large number of low bandwidth sites or large corporates with global offices.
I: CIDR
CIDR which stands for Classless Inter-Domain Routing, is an IP addressing scheme that improves the allocation of IP addresses. It replaces the old system based on classes A, B, and C (8/16/24).
- Class A - Over 16 million host identifiers
- Class B - 65,535 host identifiers
- Class C - 254 host identifiers
The problem would commonly occur when an organization required more than 254 host machines and therefore would no longer fall into class C but rather class B.
I: UNICAST
Unicast many streams of IP packets that move across networks flow from a single point, such as a website server, to a single endpoint such as a client PC. This is the most common form of information transference on networks.
I: SUBNETTING
is a logical subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.
I: PRIVATE SUBNET
A private subnet could not connect to internet. However, the instances could communicate with other instances within the VPC CIDR. AWS provides an option to allow the instance within private subnet to connect to internet through Network Address Translation (NAT) instance or NAT gateway.
I: NAT
NAT is to act as an agent between the Internet (or public network) and a local network (or private network), which means that only a single unique IP address is required to represent an entire group of computers to anything outside their networK.
I: IPSEC VPN
enables connections between an authorized remote host and any system inside the enterprise perimeter.
I: APPLICATION LOAD BALANCER
Application LB (L7) is best suited for load balancing of HTTP and HTTPS traffic and provides advanced request routing targeted at the delivery of modern application architectures, including microservices and containers. Operating at the individual request level (Layer 7), Application Load Balancer routes traffic to targets within Amazon VPC based on the content of the request.
I: RPO
refers to the amount of data that can be lost within a period most relevant to a business, before significant harm occurs, from the point of a critical event to the most preceding backup.
I: TRACE ROUTE
Trace Route will map the route that data takes from a point in a network to a specific IP server.
I: DIRECT CONNECT
AWS Direct Connect makes it easy to establish a dedicated connection from an on-premises network to Amazon VPC.
I: WEBSOCKET
is a bidirectional communication protocol that can send the data from the client to the server or from the server to the client by reusing the established connection channel. The connection is kept alive until terminated by either the client or the server.
I: TOP-LEVEL DOMAIN
A top-level domain (TLD) is the part of a domain that comes after the dot, for example, com, org or net.
Generally, you can divide TLDs into two types:
Generic top-level domains (gTLD): The most known are com, org and net. All gTLDs fall under ICANN’s policies.
Country-code top-level domains (ccTLD): all domains that are identified with a country or geographical location
I: PACKET ROUTED INTERNET
Computers send the first packet to the nearest router.
Router receives packet when the router receives a packet, it looks at its IP header. The most important field is the destination IP address, which tells the router where the packet wants to end up.
Router forwards packet the router has multiple paths it could send a packet along, and its goal is to send the packet to a router that’s closer to its final destination.
Final router forwards message if all goes well, the packet should eventually arrive at a router that knows exactly where to send it.
I: ARP
ARP (Address Resolution Protocol) finds the hardware address, also known as Media Access Control (MAC) address, of a host from its known IP address.
I: EDGE
Edge Location is a small setup in different locations. It basically provides low latency connectivity by providing static content to be available from the nearest location of the request.
I: WAN OPTIMIZATION
is a collection of technologies and techniques used to amplify efficiency of data-transfer across the WAN.
Traffic shaping Elimination of redundant data (dedupe). Data compression Data caching Streamlining data protocols Manage bandwidth or quality of service (limits)
I: LATENCY
is simply the time taken for a data packet to reach its destination after being sent.
I: OSI MODEL
- Application Layer
- Presentation Layer
- Session Layer
- Transport Layer
- Network Layer
- Data Link Layer
- Physical Layer
I: NETWORKING/WEB PROTOCOLS
ARP DHCP DNS FTP HTTP ICP IP POP3 SMTP SSL SSH TCP TELNET UDP
I: IP4
IPv4 is 32-Bit IP address
IPv4 is a numeric addressing method
IPv4 offers 12 header fields
IPv4 uses ARP (Address Resolution Protocol) to map to MAC address
I: TCP
Transmission Control Protocol (TCP) is a connection-oriented protocol that computers use to communicate over the internet. TCP provides error-checking and guarantees delivery of data and that packets will be delivered in the order they were sent.
HTTP METHODS
GET - The GET method is used to retrieve information from the given server.
HEAD - Same as GET, but transfers the status line and header section only.
POST - A POST request is used to send data to the server.
PUT - Replaces all current representations of the target resource with the uploaded content.
DELETE - Removes all current representations of the target resource given by a URI.
CONNECT - Establishes a tunnel to the server identified by a given URI.
OPTIONS - Describes the communication options for the target resource.
TRACE - Performs a message loop-back test along the path to the target resource.
DNS RECORDS
A Maps domain names to IPv4 addresses
AAAA Maps domain names to IPv6 addresses
CNAME Redirects a domain to a different domain
PTR Resolves IPv4 or IPv6 addresses to domain names
NS Provides a list of the authoritative name servers responsible for the domain
MX Provides the domain names of mail servers that receive emails on behalf of a domain
SOA Provides important details about a DNS zone; required for every DNS zone
TXT Provides any type of descriptive information in text format
I: LAYER 3
Layer 3 (network layer) and its protocol is the Internet Protocol or IP. Traditionally, the network device most associated with Layer 3 has been the router, which allows you to connect devices in different IP networks.
I: LAYER 7
Layer 7 (application layer) is the “closest to the end user”. Applications that work at Layer 7 are the ones that users interact with directly. A web browser (Google Chrome, Firefox, Safari, etc.) or other app - Skype, Outlook, Office - are examples of Layer 7 applications.
I: ROUTE53
Amazon Route 53 is a highly available and scalable Domain Name System (DNS) web service. You can use Route 53 to perform three main functions in any combination: domain registration, DNS routing, and health checking.
I: OSPF
is a link-state routing protocol that is used to find the best path between the source and the destination router using its own Shortest Path First.
I: IGRP
Interior gateway routing protocol created in part to defeat the confines of RIP (Routing Information Protocol) in large networks.
I: EIGRP
a network protocol that enables routers to exchange information more efficiently than earlier network protocols, such as Interior Gateway Routing Protocol (IGRP) or Border Gateway Protocol (BGP).
I: ROUTER
connects multiple switches, and their respective networks, to form an even larger network.
I: MULTICAST
is where data transmission is addressed to a group of destination computers simultaneously
I: BROADCAST
streams from a single point to all possible endpoints within reach on the network, which is generally a LAN. This is the easiest technique to ensure traffic reaches its destinations.
I: PUBLIC SUBNET
A public subnet routes 0.0.0.0/0 through an internet gateway (igw). EC2 instances within public subnet could connect to internet through instance public IP. The instances in the public subnet could send outbound traffic to internet. However, all incoming request to your instance is blocked by your public subnet.
I: SSL VPN
can be configured to enable connections only between authorized remote hosts and specific services offered inside the enterprise perimeter.
I: NETWORK LOAD BALANCER
Network LB (L4) is best suited for load balancing of TCP, UDP, and TLS traffic where extreme performance is required.
I: RTO
is the duration of time and a service level within which a business process must be restored after a disaster to avoid unacceptable consequences associated with a break in continuity. In other words, the RTO is the answer to the question: “How much time did it take to recover after notification of business process disruption?”
I: HTTP CALL
The client submits an HTTP request to the server, and after internalizing the message, the server sends back a response.
I: IPv6
128-Bit IP address
is an alphanumeric addressing method
offers 8 header fields
uses NDP (Neighbour Discovery Protocol) to map to MAC address
I: UDP
User Datagram Protocol (UDP) is a connectionless protocol that works just like TCP but assumes that error-checking and recovery services are not required. Instead, UDP continuously sends datagrams to the recipient whether they receive them or not.
