IT Networking
Tools and methods for DNS, DHCP, VLAN, routing, Wi-Fi, LINK, TITLE/IP, latency, MTU and network diagnostics
Network & VLAN Planner
Network & VLAN Planner — practical IT resource from IT Toolbox.
Knowledge hubNetwork ports and protocols
Find TCP and UDP ports, protocol uses, security considerations and troubleshooting references for network administration.
ResourceNetwork & Wi-Fi Center
Network & Wi-Fi Center — practical IT resource from IT Toolbox.
ResourceFree IT tools
Use free browser-based IT tools for networking, DNS, Windows, email, security, diagnostics, PDF workflows and day-to-day administration.
ResourceNetwork scheme
Draw a network topology withGolden, switch, servers, VLAN, Wi-Fi, cloud and VPN, then export to SVG, PNG, JSON or PDF
Command / scriptCreate a Windows Network Diagnostic Report
Consolidates IP configuration, routes, DNS and several connectivity tests into a text file
ResourceInternet or network inaccessible
Guided diagnostic of, Internet access or network unavailable: IP, gateway, DNS, DHCP, Wi-Fi, routing and connectivity
ResourceNetwork flow matrix
Document your Source, Destination, Port, Protocol, Action and Justification network feeds and then export to CSV, JSON or PDF
Knowledge hubHome
Free tools, procedures, diagnostics, scripts, dictionary and practical resources for IT technicians, system administrators and SMEs
IT dictionarySubnet Mask
The value that separates the network part and the host part of an IP address
IT dictionarymDNS
mDNS is a concept or mechanism used in network & dns to resolve locally without server names DNS Central.
IT dictionaryDHCP Relay
A mechanism that transmits DHCP requests between subnets
IT dictionaryEDNS
EDNS is a concept or mechanism used in network & dns to extend protocol capabilities DNS.
IT dictionaryNetwork Port
A logical number identifying a service or application on an IP address.
IT dictionaryReverse DNS
Reverse DNS is a concept or mechanism used in network & dns to resolve an IP address to a name via DNS Inverse.
ResourceHow to find an STP loop on a network
This BOAI guide provides a structured method for finding a loop on a network without multiplying unnecessary changes
ResourceHow to test a TCP port with PowerShell
Test-Net-Migration allows you to quickly check if a station can reach a server on a specific TIP port, without installing any additional tool.
ResourceHow to renew an IP address DHCP under Windows
Force Windows to abandon and then re-demand an IP address to a DHCP server
ResourceHow to know the DNS servers used on Windows
Identify DNS solvers actually configured on a Windows desktop
ResourceHow to diagnose DHCP Snooping
This BOAI guide provides a structured method for diagnosing dhcp snooping without multiplying unnecessary changes
ResourceHow to check a DNS AXFR zone transfer
This BOAI guide provides a structured method for checking a zone transfer dns axfr without multiplying unnecessary changes
ResourceVLAN vs Subnetwork: What difference?
A VLAN segmentes an Ethernet network logically. A subnet cuts the IP address space. They are often associated, but they belong to the network
ResourceDNS vs DHCP: What difference?
DNS and DHCP are two essential network services, but they do not perform the same role. DNS translates names into IP addresses, while DHCP
TroubleshootingSMB network sharing inaccessible from Windows
A UNC path or network drive no longer opens while the server sometimes seems reachable
ResourceTCP vs UDP: What Is the Difference?
TITLE focuses on reliability and data order. UDP focuses on simplicity and speed, without guaranteeing delivery
TroubleshootingA network printer is offline
Windows indicates that l, network printer is offline or the prints remain pending
TroubleshootingNetwork loop after adding a switch
The network becomes very slow or unstable after connection to a new switch
ProcedureCreate a dedicated vMotion network
Controlled procedure to create a dedicated vmotion network
ProcedureResolve an automatic IP address or unavailable DHCP issue
Diagnose APIPA and missing DHCP leases through adapter, VLAN, relay, scope and DORA checks with a controlled pilot renewal.
ProcedureDiagnose an inaccessible TCP port
Check the network path, l, service listening and firewalls when an application does not join a server
ProcedureSolve a DNS problem on Windows
Diagnose Windows DNS with resolver-specific queries, suffix and Hosts checks, cache evidence, timing and bounded network tracing.
ProcedureDiagnose unstable Wi-Fi on Windows
Analyze signal quality, pilot, band used and intermittent cuts
ProcedureCreate a VLAN on a FortiGate
Create a VLAN interface, its DHCP and the necessary policies without disrupting existing networks
ResourceWindows network — diagnostic memo
Windows commands for IP configuration, DHCP, DNS, routes, TCP ports and network troubleshooting.
ResourceNetwork ports — memo form
Common TCP and UDP ports, their services and practical checks for network administration.
ResourceDNS — memo form
DNS record types, resolver checks, delegation, caching and commands for diagnosing name resolution.
ResourceLinux — Essential commands
Linux commands for services, logs, processes, storage, networking, DNS, permissions and system diagnostics.
ResourcePowerShell — Essential commands
PowerShell commands for Windows administration, services, events, networking, files and remote sessions.
ResourceVMware — operating memo
VMware vSphere and ESXi checks for virtual machines, snapshots, datastores, networking, logs and safe maintenance.
Knowledge hubFortiGate
Tools, diagnostics, commands and resources to administer and troubleshoot theFortiGate and FortiOS
Knowledge hub3CX & VoIP
3CX and VoIP troubleshooting:SIP trunks, DECT, SBC, NAT, RTP, audio quality, certificates, phones and backups.
Knowledge hubCybersecurity
Defensive resources for phishing, ransomware, compromised accounts, MFA, hardening,19th, incidents and protection of backups
Knowledge hubStorage / NAS / SAN
Company storage: Rsid, SMART, NAS, SMB/NFS, iSCSI, MPIO, LUN, SAN, ZFS, LVM, PORTOS, capacity and performance
Knowledge hubPrinters / Scanning / SMB
Printer troubleshooting, printing servers, SMB scan-to-folder, SMTP-Band-to-mail, drivers, WSD, TWAIN and WIA