Networking Fundamentals Flashcards
(186 cards)
1
Q
Layers of OSI Model
A
1 - Physical
2 - Data Link
3 - Network
4 - Transport
5 - Session
6 - Presentation
7 - Application
2
Q
Ethernet frame
A
Preamble
Start frame delimiter
Destination MAC
Source MAC
EtherType
Payload
FCS
3
Q
IP Packet header
A
Header
Source IP address
Destination IP address
Payload
4
Q
TCP Header
A
Source Port
Destination Port
Sequence number
Acknowledgement number
DO
RSV
Flags
Window Size
Checksum
Urgent pointer
5
Q
UDP Header
A
Source Port
Destination Port
Length
Checksum
6
Q
TCP flags
A
SYN - synchronize, establish connection
ACK - acknowledge
FIN - finish
PSH - push, do not buffer
URG - urgent
RST - reject packet
7
Q
MTU
A
maximum transmission unit - largest PDU size that can be sent in one transmission
8
Q
Mesh topology
A
Multiple connections between nodes
9
Q
Star/hub-and-spoke topology
A
All nodes connected to a central device (switch or hub)
10
Q
Bus topology
A
All nodes connected to a central line (bus) that must be terminated at each end.
11
Q
Ring topology
A
Each device is connected to two other devices on either side. Mostly unidirectional.
12
Q
Hybrid topology
A
a combination of different types
13
Q
Peer-to-Peer network
A
Each node is connected to each other acting as both server and client
14
Q
Client-server
A
Client machines want to use resources; servers have these resources
15
Q
LAN
A
Local Area Network
16
Q
MAN
A
Metropolitan area network - a large network that connects machines in a local area - larger than a LAN but smaller than a WAN
17
Q
WAN
A
Wide area network - spans a large area, connects multiple LANs together
18
Q
WLAN
A
Wireless LAN
19
Q
PAN
A
Personal area network - Bluetooth/NFC connected devices (headphones + headset, etc.)
20
Q
CAN
A
Campus Area Network
21
Q
SAN
A
Storage Area Network - a networked pool of storage devices that can be accessed by connected machines as though they were local drives
22
Q
SDWAN
A
Software-defined Wide Area Network - Cloud-based software controls routing of data, rather than physical devices Instead of a central data center, these things are in the cloud.
23
Q
MPLS
A
Multiprotocol label switching - routs traffic using labels instead of network addresses. Useful for connecting remote sites to each other through the cloud; can offer QoS; labels are “pushed” on to packets when they enter cloud and “popped” off when they leave.
24
Q
mGRE
A
Multipoint Generic routing encapsulation. Used to dynamically link remote sites together (connections are established as needed and destroyed when finished).
25
Demarc
Demarcation point - where your equipment ends and the ISP's begins
26
Smartjack
Can convert between signal types, buffer or regenerate signals, etc.
27
vSwitch
Virtual switch
28
vNIC
Virtual network interface card - NIC of a virtual server (or other machine)
29
NFV
Network function virtualization - replacing physical network devices with virtual versions; managed by a VMM (Hypervisor)
30
Satellite internet
wide coverage area but high latency
31
DSL
Uses old phone lines - tops out at 24 Mbps
32
Cable internet
Fast speed, wide availability
33
Leased line internet
fast dedicated fixed-bandwidth connection (usually fiber)
34
Metro-optical
Metropolitan ethernet connection
35
Cat 5 UTP
Max. distance: 100m
Max Bandwidth: 100 Mbps - 1 Gbps
36
Cat 5e UTP
Max. distance: 100m
Max Bandwidth: 1 Gbps
37
Cat 6 UTP
Max. distance: 55m
Max Bandwidth: 10 Gbps
38
Cat 6a UTP
Max. distance: 100m
Max Bandwidth: 10 Gbps
39
Cat 7 UTP
Max. distance: 100m
Max Bandwidth: 10+ Gbps
40
Cat 8 UTP
Max. distance: 100m
Max Bandwidth: 25 / 40 Gbps
41
Coaxial RG-6
Used for cable internet; has F-type connector; 75 Ohms
42
Twinaxial
2 inner conductors that share an outer conductor
43
TIA/EIA-568A
Green-white
Green
Orange-white
Blue
Blue-white
Orange
Brown-white
Brown
44
TIA/EIA-568B
Orange-white
Orange
Green-white
Blue
Blue-white
Green
Brown-white
Brown
45
Single-mode fiber
Uses lasers; typically yellow sheath
46
Multimode fiber
Uses LEDs; typically orange sheath
47
LC connector
48
ST connector
49
MTRJ connector
50
APC (fiber connection)
Angled physical contact
51
UPC (fiber connection)
Ultra Physical Contact (rounded tip)
52
RJ-11
smaller connector used for phone lines
53
RJ-45
larger connector for UTP/STP
54
F-Type connector
Used for coaxial cable
55
Media converters
used to convert one type of signal to another (fiber to copper, etc)
56
SFP
Small form-factor pluggable
57
SFP+
Enhanced version of SFP, can support up to 10 Gbit
58
QSFP
quad - SFP supports up to 40 Gbit
59
Patch panel
Cables come in from long runs, terminate at the back of patch panel. Patch cables are used to connect from panel to switches.
60
Fiber distribution panel
patch panel for fiber
61
66 punchdown block
used to connect phone lines (older)
62
110 punchdown block
newer punchdown block used for phone lines and network cables (up to cat5e)
63
Krone punchdown block
a type of punchdown block that uses several enhancements
64
Bix punchdown block
type of punchdown block
65
10BASE-T
10 Mbit
Baseband
Twisted pair
100 m max run
66
100BASE-TX
100 Mbit
Baseband
Twisted pair
100 m max run
67
1000BASE-T
1000 Mbit/1Gbit
Baseband
Twisted pair
100 m max run
68
10GBASE-T
10 Gbit
Baseband
Twisted pair
100 m max run
69
40GBASE-T
40 Gbit
Baseband
Twisted pair
100 m max run
70
100BASE-FX
100 Mbit
Baseband
Multimode fiber
2 km max run
71
100BASE-SX
100 Mbit
Baseband
Multimode fiber
72
1000BASE-SX
1000 Mbit/1Gbit
Baseband
Multimode fiber
500 m max run
73
1000BASE-LX
1000 Mbit/1 Gbit
Baseband
Single-mode fiber
5 km max run
74
10GBASE-SR
10 Gbit
Baseband
Multimode fiber
26-400 m max run
75
10GBASE-LR
10 Gbit
Baseband
Single-mode fiber
10 km max run
76
CWDM
Coarse wavelength division multiplexing - allows bidirectional communications on a single fiber; supports up to 18 channels
77
DWDM
Dense wavelength division multiplexing - allows bidirectional communication on a single fiber ; supports more than 200 channels
78
WDM
Bidirectional wavelength division multiplexing - allows bidirectional communication on a single fiber
79
Private IP addresses
10.x.x.x
172.16.x.x - 172.31.x.x
192.168.x.x
(RFC 1918)
80
NAT
Network Address Translation - a gateway router has a single public IP address and every machine on the internal LAN has a private address
81
PAT
Port Address Translation - having more than one internal machine share a public IP address by using different port numbers (same IP address, different port numbers)
82
APIPA Address
169.254.x.x
83
EUI-64
A method in IPv6 whereby a machine can assign itself an interface ID
84
Multicast
224.0.0.0 to 239.255.255.255
85
Unicast
A transmission sent to a single address
86
Anycast
a single IP address is shared between multiple devices (usually servers)
87
Broadcast
IPv4: the highest available host
88
Link local
IPv6 address that is used to communicate locally;
FE80::/10
89
Loopback
IPv4: 127.0.0.1
IPv6: ::1
90
Default gateway
The private address of the gateway router
91
VLSM
Variable-length subnet mask: subnetting a subnet
92
Class A IP address
0-126 /8
93
Class B IP address
128-191 /16
94
Class C IP address
192-223 /24
95
Class D IP address
224-239 (reserved for multicasting)
96
Class E IP address
240-254 (experimental)
97
CIDR notation
Classless inter-domain routing
98
IPv6 Tunneling
Encapsulating IPv6 traffic in an IPv4 packet in order to help transition to IPv6
99
Dual Stack
Running IPv4 and IPv6 at the same time
100
Shorthand notation
Eliminate leading zeroes
Can replace a single block of all zeroes with ::
101
Router Advertisement
IPv6 routers periodically send out availability and configuration messages
102
SLAAC
Stateless address autoconfiguration - IPv6 analogue to DHCP
103
Virtual IP
A virtual IP address
104
Subinterfaces
Dividing a single physical interface into more than one logical interface
105
FTP
TCP 20 - active transfer of data
TCP 21 - control data
106
SSH
TCP 22; Secure remote console access
107
SFTP
TCP 22; Secuire file transfer (uses SSH, so shares port number)
108
Telnet
TCP 23; Unencrypted remote console access
109
SMTP
TCP 25; Server-to-server email communication
110
DNS port
UDP 53; Converts domain names to IP addresses
111
DHCP ports
UDP 67/68
112
TFTP
UDP 69; simplified file transfer; no authentication (not generally used in production)
113
HTTP port
TCP 80
114
POP3
TCP 110; Receive emails from server
115
NTP port
UDP 123
116
IMAP
TCP 143; management of email inbox from multiple clients
117
SNMP
UDP 161; used to gather statistics from network devices
SNMP Traps sent from UDP 162
118
LDAP
TCP 389; Lightweight Directory Access Protocol; Stores and retrieves information in a network directory
119
HTTPS port
TCP 443
120
SMB
TCP 445; Used by Windows for file sharing, printer sharing, etc.
121
Syslog
UDP 514; devices send message logs to a central repository (SIEM)
122
SMTP w/ TLS
TCP 587
123
LDAPS port
TCP 636
124
IMAP over SSL
TCP 993
125
POP3 over SSL
TCP 995
126
Microsoft SQL server
TCP 1433
127
Oracle SQLnet
TCP 1521
128
MySQL port
TCP 3306
129
RDP
TCP 3389; Windows Remote Desktop Protocol
130
SIP
TCP 5060/5061; Used to set up/manage VoIP sessions
131
ICMP
Internet Control Message Protocol - used to send bits of info; works at IP level, no data (ping for example)
132
TCP
Transport Control Protocol - connection-oriented; 3-way handshake, has methods of sequencing packets in case of out of order delivery
133
UDP
User Datagram Protocol - low overhead, no connection, unreliable delivery
134
DHCP Process
Client sends DHCP Discover (UDP 68 to broadcast)
DHCP server sends DHCP Offer to Client (UDP 68 to broadcast)
Client sends DHCP Request to server (UDP to broadcast)
DHCP server sends DHCP Acknowledgement to broadcast
135
DHCP Scope
IP address range (along with excluded addresses)
136
DHCP Exclusion Range
The range of addresses that the DHCP server won't hand out
137
DHCP Reservation
Specific addresses that are reserved for specific devices
138
DHCP Dynamic Assignment
Addresses are assigned from a pool of addresses. They are reclaimed after a period of time.
139
DHCP Static Assignment
Administratively configured addresses (linked to a MAC address)
140
DHCP Lease Time
How long a device keeps an IP address
141
DHCP Relay
Sends DHCP messages through a router to other networks (DHCP messages are broadcasts)
142
DNS
Domain Name System - translates human-readable names to IP addresses.
143
DNS A / AAAA
Address reccord - defines the IP address of a host
A - IPv4
AAAA - IPv6
144
DNS CNAME
Canonical name: Provides an alias to a server
Example: "mail", "chat", "ftp" can all be set to resolve to "www" in the name records
145
DNS MX
Mail Exchanger record - contains the name of the mail server - perform additional queries to find IP address
146
DNS SOA
Start of Authority - describes the DNS zone details (zone name, serial number, refresh/retry/expiry, caching/TTL)
147
DNS PTR
Pointer - Used for reverse lookups
148
DNS TXT
Text - human-readable text information (public information)
SPF protocol (sender policy framework)
DKIM (domain keys identified mail)
149
DNS SRV
Service records - helps to find a specific service (Windows Domain Controller, Instant Messaging, VoIP, etc.)
150
DNS NS
Lists name servers for a domain
151
DNS Global Heirarchy
13 Root server clusters
Hundreds of generic TLD (.com, .org, etc.)
Over 275 country code TLD
152
DNS Zone Transfer
Replicates a DNS database. Changes made on a primary DNS server will be replicated on redundant servers
153
DNS Authoritative Name Server
The authority for the specific domain. Non-authoritative info is usually from cached info, rather than straight from the server itself
154
DNS Reverse Lookup
Provide the server with an IP address and it gives you the domain name.
155
DNS Recursive Lookup
Sends request to DNS server, DNS server does the work and then reports back (server keeps large cache)
156
DNS Iterative Lookup
Local device does all queries (rather than having a name server do it for you)
157
Internal DNS
Configured and maintained locally
Contains info on internal devices
158
External DNS
Managed by third party (Google, etc.)
159
NTP
Used to keep time synchronized between network devices
160
NTP Stratum
Describes "distance" from original reference clock
Stratum 0 - Atomic Clock
Stratum 1 - Primary time servers
Stratum 2 - Synced to stratum 1 servers
etc.
161
NTP Clients
Requests time updates from NTP server
162
NTP Servers
Responds to time requests from NTP clients
163
Core (Network architecture)
The "center" of the network, containing Web servers, databases, apps, etc.
164
Distribution / aggregation layer
Midpoint between core and users, communication between access switches, manages path to end users
165
Access/Edge layer
Users connect to these switches
166
Data plane (SDN)
Infrastructure; processing frames/packets, forwarding, trunking, encrypting, NAT, etc.
167
Control plane (SDN)
Manages actions of data plane; routing tables, session tables, NAT tables, dynamic routing protocols
168
Management plane (SDN)
Configure/manage the devices
169
Spine-and-Leaf
Servers connect to leaf switches, which connect to all spine switches. Leafs do not connect to each other. (Top-of-rack switching)
170
North-South Traffic
In/out to an outside device. Slower, must have tighter security.
171
East-West Traffic
Traffic between devices in the same data center
172
FCoE (SAN)
Fibre Channel over Ethernet. No specialized hardware required.
Not routable, runs within a single broadcast domain.
173
Fibre Channel (SAN)
Specialized high-speed topology to connect servers to storage. Requires a specialized Fibre Channel switch.
Can be used with fiber OR UTP
174
iSCSI (SAN)
SCSI commands over an IP network. Makes a remote disk look and operate like a local disk.
175
Public Cloud
Available to everyone on the Internet.
176
Private Cloud
Your own virtual datacenter
177
Hybrid Cloud
A combination of public and private clouds
178
Community Cloud
Several organizations share same goal/requirements (example: a provider that advertises specifically to healthcare)
179
SaaS
On-demand software; no local installation. GDrive, email, etc. Provider is responsible for security.
180
IaaS
Hardware as a service; outsourcing equipment. You're still responsible for the management and security. Ex. Web server providers.
181
PaaS
Middle ground between IaaS and SaaS. Someone else manages the platform. You supply the code. Provider can supply building blocks.
182
DaaS
Virtual desktops - applications run on a remote server. Local device is a keyboard, mouse, and screen.
183
Infrastructure as Code
All hardware can be virtualized and updated in code.
184
Multitenancy
Many different clients are using the same cloud infrastructure. This brings costs down.
185
Elasticity
Scale up or down as needed
186
Scalability (Cloud)
