What type of ISP website hosting packages are common for organizations?
Dedicated server—The ISP allocates your own private server computer. This type of service is usually unmanaged (or management comes at additional cost).
Virtual private server (VPS)—The ISP allocates you a virtual machine (VM) on a physical server.
Cloud hosting—Your website is run on a cloud over several hardware computers, allowing more scalability if demand patterns change.
Shared hosting—Your website is hosted within a private directory on a shared server. Performance can be severely affected by other sites hosted on the server, because all the sites are competing for the same resources.
What is the difference between active and passive FTP?
Active: Client uses PORT command
FTP client provides IP and port for server to connect to the data channel.
Client side must open a range of ports for inbound connection, usually blocked by firewall
Passive: Client uses PASV command
FTP server provides IP and port for the client to connect to the data channel.
Server side must open a range of ports for inbound connection, usually NOT blocked by firewall
What is TFTP?
Trivial file transfer protocol
connectionless protocol that works over UDP 69.
only suitable for transferring small files.
TFTP server is most commonly used by legacy network appliances.
Has no security mechanisms, and appliances are no longer as resource constrained as they were in the early days of networking.
What is SFTP?
Secure file transfer protocol.
A secure link is created between the client and server using SSH over TCP port 22
FTPS is tricky to configure when there are firewalls between the client and server.
What are the 2 ways of configuring FTP over TLS?
Explicit TLS (FTPES)—Use the AUTH TLS command to upgrade an insecure connection established over TCP port 21 to a secure one. The data connection for the actual file transfers can also be encrypted (using the PROT command).
Implicit TLS (FTPS)—Negotiate an SSL/TLS tunnel before the exchange of any FTP commands. This mode uses TCP port 990 for the control connection.
FTPES is usually the preferred method due to being easier to configure with firewalls.
How is File/Print sharing services provided on Windows?
SMB (Server Message Block)
Support for SMB on Linux based machines is provided by what?
By the Samba Software suite.
What is a NAS?
Network attached Storage.
A device dedicated to performing a file server role.
A NAS appliance is accessed via an IP address or domain name.
Most NAS devices support some level of Redundant Array of Independent Disks (RAID).
The main drawback of NAS is that it shares bandwidth with other network applications.
What does a database do?
provisions information in a format that can be read and updated through some type of query language.
What are the 2 main types of databases?
Relational databases: Relational databases store information in tables with rows (records) and columns (fields).
Relationships between data fields in different tables is created using key fields that uniquely identify each record.
Relational databases are operated using Structured Query Language (SQL)
SQL has been implemented in relational database management system (RDBMS) platforms by several different vendors.
NoSQL or Not only SQL: Rather than highly structured relational tables, NoSQL data can use a variety of formats, such as key-value pairs or wide columns (where rows do not have to have the same set of fields).
Typically accessed using an application programming interface (API) over HTTPS.
What are the 2 ways for SMTP to use TLS?
STARTTLS: AKA explicit TLS or opportunistic TLS. Its a command that upgrades an existing insecure connection to use TLS.
A deprecated method but still widely used.
Port 587
Implicit TLS: This establishes the secure connection before any SMTP commands. The preferred method.
Port 465
What is SMTP?
Simple Mail Transfer Protocol.
specifies how email is delivered from one system to another.
The SMTP servers for the domain are registered in DNS using mail exchange (MX) and host (A/AAAA) records.
SMTP does not queue messages indefinitely, if it times out it returns a NDR (Non delivery report.) to the sender.
What is IMAP (Internet Message Access Protocol)
The most widely used mail retrieval protocol.
Supports permanent connections to a server and connecting multiple clients to the same mailbox simultaneously.
Also allows a client to manage the mailbox on the server.
Uses TCP pot 143 secure is 993
What is TDM based PBX
time division multiplexing and private branch exchange
A TDM-based PBX connects to the telecommunications carrier over a digital trunk line, which will support multiple channels (inward and outward calls). Supports features such as call waiting, music on hold, and voicemail. Can multiplex separate voice and data channels for transmission over a single cable.
TDM PBX is supplied as vendor-specific hardware.
What is VoIP PBX?
What TDM PBX is being replaced by.
It establishes connections between local VoIP endpoints with data transmitted over the local Ethernet network.
Can also route incoming and outgoing calls from and to external networks.
Will also support features such as music on hold and voicemail.
Can be implemented as software
VoIP PBX would normally be placed at the network edge and be protected by a firewall
What protocols are designed to support real time services? (i.e. VoIP, media streaming etc.)
Session Control- Used to establish, manage, and disestablish communications sessions. Can handle tasks such as user discovery, availability advertising, and negotiating session parameter
Data transport—Handles the delivery of the actual video or voice information.
Quality of service (QoS)—Provides information about the connection to a QoS system, which in turn ensures that voice or video communications are free from problems, such as dropped packets, delay, or jitter.
What is SIP? (session Initiation Protocol)
One of the most widely used session control protocols.
Typically runs over UDP or TCP ports 5060 (unsecured) and 5061 (SIP-TLS).
What does RTP and RTCP do?
Real time protocol, and Real time control protocol.
Paired protocols for delivering and managing audio/video data in real time.
RTP carries the media stream.
RTCP monitors the QoS.
What is a VoIP phone?
Handset or software client that implements a type of voice over Internet Protocol (VoIP) to allow a user to place and receive calls.
Handsets can use Power over Ethernet (PoE)
There are also wireless handsets that work over 802.11 Wi-Fi networks.
For connection security it uses SIPS which uses digital certificates to authenticate endpoints and establish a TLS tunnel.
What is MTTF?
Mean Time To Failure.
Used to express the expected lifetime or reliability of non-repairable components, providing an average time until failure.
What is MTTRr?
Mean time to repair.
Measure of time take to correct a fault so that the system is restored to full operation.
What is MTBF?
Mean Time Between Failures.
Used for repairable components, indicating the average time between failures
What is FHRP?
First hop redundancy protocols.
Provides failover routers to serve as the default gateway for a subnet. AKA VRRP and HSRP
What is HSRP?
Hot Standby Router Protocol
Allows multiple physical routers to serve as a single default gateway for a subnet.
Standby router monitors the status of the active router and takes over if the active becomes unavailable.
This triggers the selection of new standby router from the remaining routers in the group.
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Topologies15
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OSI Model15
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SOHO Networks7
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Troubleshooting methodology2
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Ethernet3
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Wiring Implementation11
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Ports6
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Fiber Optic Cables17
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Common acronyms4
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Physical installation factors.. Racks etc12
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Cable Troubleshooting18
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Network interfaces8
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Network Threats and Attacks5
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Authentication2
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Hubs Bridges and Switches8
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Cat cables9
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switch port configuration and troubleshooting33
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IP47
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routing techniques50
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Headers2
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Transport and application layer protocols52
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application services32
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Supporting Network Management99
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Explaining Network security concepts53
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Applying Network Security Features56
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Supporting Network Security Design30
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Configuring Wireless networks67
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Comparing remote access methods25
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Summarizing cloud concepts9
