Network Knowledge Base

EMAIL

MX Lookup: Complete Guide to Mail Exchange Records

Everything you need to know about MX records: configuration, priority, troubleshooting, and best practices to ensure email delivery.

MX Lookup Read >

EMAIL

SPF Lookup: How to Protect Your Domain from Email Spoofing

Everything about SPF: from record syntax to troubleshooting, including DNS limits and configuration best practices.

SPF Lookup Read >

EMAIL

DKIM Lookup: Email Digital Signatures Explained

In-depth guide to DKIM: from cryptography to configuration, everything you need to guarantee the authenticity of your emails.

DKIM Lookup Read >

EMAIL

DMARC Lookup: The Policy that Blocks Domain Spoofing

What DMARC is, how it works, and why every domain should have an active policy to prevent phishing and spoofing.

DMARC Lookup Read >

EMAIL

DMARC Generator: Create the Perfect DMARC Record in 2 Minutes

Not sure how to create a DMARC record? Our guide walks you through generating the perfect record for your domain step by step.

DMARC Generator Read >

EMAIL

SMTP Diagnostics: How to Test and Troubleshoot Your Mail Server

Practical guide to SMTP diagnostics: test your mail server, identify vulnerabilities, and resolve email delivery issues.

SMTP Diagnostics Read >

EMAIL

Email Header Analyzer: How to Read and Interpret Email Headers

Learn to read email headers like a professional: from message routing to authentication, every header explained.

Email Header Analyzer Read >

EMAIL

BIMI Lookup: Display Your Brand Logo in the Email Inbox

BIMI brings your logo to the inbox: learn how to configure it, the technical requirements, and the impact on brand reputation.

BIMI Lookup Read >

EMAIL

MTA-STS: Mandatory Encryption for Email Transfer

MTA-STS enforces mandatory TLS for your domain's emails. Learn how to configure it and why it is essential for security.

MTA-STS Lookup Read >

EMAIL

TLS-RPT: Reports on Email TLS Failures

TLS-RPT alerts you when email TLS connections fail. Learn how to configure it and interpret the reports.

TLS-RPT Lookup Read >

DNS

DNS Lookup: The Complete Guide to DNS Record Resolution

DNS is the phonebook of the Internet. Learn how to query it, what records exist, and how to solve the most common problems.

DNS Lookup Read >

DNS

CNAME Lookup: How DNS Aliases Work and When to Use Them

CNAME records create aliases in DNS. Learn when to use them, the rules to follow, and how to diagnose chain issues.

CNAME Lookup Read >

DNS

Reverse DNS: From IP to Hostname with PTR Records

Reverse DNS translates IPs into hostnames. Learn why it is essential for email deliverability and network security.

Reverse DNS Read >

DNS

NS Lookup: The Authoritative Nameservers of Your Domain

Nameservers are the foundation of your domain. Learn how to verify them, ensure redundancy, and diagnose delegation issues.

NS Lookup Read >

DNS

SOA Lookup: The Authority Record of the DNS Zone

The SOA record is the heart of the DNS zone. Learn what it contains, how to read it, and why it matters for DNS management.

SOA Lookup Read >

DNS

TXT Lookup: All the Secrets of DNS TXT Records

TXT records have a thousand uses: email authentication, domain verification, service configuration. A complete management guide.

TXT Lookup Read >

DNS

DNS Health Check: Complete Diagnostics of Your DNS Configuration

A complete check-up of your domain's DNS: identify problems, inconsistencies, and vulnerabilities before they cause downtime.

DNS Health Check Read >

DNS

ASN Lookup: Autonomous System Numbers and Network Topology

From IP to provider: the ASN Lookup reveals who manages an address block, the BGP routes, and the network structure.

ASN Lookup Read >

DNS

Subdomain Finder: Discover the Hidden Infrastructure of a Domain

Subdomains reveal infrastructure. Learn how to find them, why it matters for security, and how to protect your perimeter.

Subdomain Finder Read >

DNS

DNS Propagation: Monitor Global DNS Propagation in Real Time

Modified a DNS record? Verify in real time from 20+ servers worldwide whether propagation is complete.

DNS Propagation Read >

SECURITY

SSL Check: Complete Verification of Your Site's SSL/TLS Certificate

Is your SSL certificate configured correctly? Learn how to verify it, what the grade means and how to improve HTTPS security.

SSL Check Read >

SECURITY

Blacklist Check: How to Verify and Get Off DNSBLs

Blacklists block your emails. Learn how to check 100+ DNSBLs, how to delist and how to prevent future blacklisting.

Blacklist Check Read >

SECURITY

Port Scanner: Identify Exposed Services and Attack Surface

Which ports are open on your server? The Port Scanner identifies exposed services and vulnerabilities in firewall configuration.

Port Scanner Read >

SECURITY

Open Relay Test: Protect Your SMTP Server from Spam

An open relay allows anyone to use your server to send spam. Learn how to test and protect your SMTP.

Open Relay Test Read >

SECURITY

Security Headers: Protect Your Site with HTTP Security Headers

HTTP security headers are your site's defense against XSS, clickjacking and HTTPS downgrade. Learn which to configure and how.

Security Headers Read >

SECURITY

TLS Cipher Test: Cipher Suite and TLS Configuration Analysis

Cipher suites determine the security of TLS connections. Learn which are secure, which are obsolete and how to configure them.

TLS Cipher Test Read >

SECURITY

Certificate Chain: Validate the Entire SSL Certificate Chain

A missing intermediate certificate causes SSL errors for some users. Learn how to verify and complete the chain.

Certificate Chain Read >

SECURITY

CAA Record Lookup: Control Who Can Issue Certificates for Your Domain

CAA records prevent unauthorized SSL certificate issuance for your domain. Guide to configuration and verification.

CAA Record Lookup Read >

NETWORK

Ping: Complete Guide to Reachability and Latency Testing

Ping is the most widely used network diagnostic tool in the world. Learn how to interpret RTT, packet loss, and TTL.

Ping Read >

NETWORK

Traceroute: Map the Path of Packets Hop by Hop

Traceroute shows every router between you and the destination. Learn how to read it to diagnose network issues.

Traceroute Read >

NETWORK

HTTP Headers: Complete Analysis of Server Response Headers

HTTP headers reveal everything about your server configuration: caching, security, redirects, and performance. A guide to analysis.

HTTP Headers Read >

NETWORK

IP Geolocation: Locate Any IP Address in the World

From IP to map: discover the location, ISP, ASN, and detailed information about any public IP address.

IP Geolocation Read >

NETWORK

WHOIS Lookup: Everything About Domain Registration Information

WHOIS reveals who owns a domain, when it expires, and who the registrar is. A guide to querying and interpreting the data.

WHOIS Lookup Read >

NETWORK

What Is My IP: Discover Your Public IP Address and Network Info

What is your public IP? Find out instantly with geolocation, ISP, and detailed network information.

What Is My IP Read >

NETWORK

Speed Test: Measure Download, Upload, and Latency of Your Connection

Is your connection as fast as promised? Measure download, upload, and ping with our Speed Test and find out.

Speed Test Read >

NETWORK

Domain Health: The Complete Check-Up for Your Domain

A single tool to verify DNS, email, SSL, and security for your domain. Discover your health score and what to improve.

Domain Health Read >

UTILITY

Subnet Calculator: Guide to IP Subnet Calculation

Subnetting is fundamental to network management. Learn how to calculate subnets, host ranges and broadcast addresses with CIDR notation.

Subnet Calculator Read >

UTILITY

Password Generator: Create Secure and Unbreakable Passwords

Weak passwords are the leading cause of compromise. Generate cryptographically secure passwords with customizable options.

Password Generator Read >

UTILITY

Base64 Encode/Decode: Complete Guide to Base64 Encoding

Base64 converts binary data to ASCII text. Learn how it works, where it is used (JWT, email, data URI) and mistakes to avoid.

Base64 Encode/Decode Read >

UTILITY

URL Encode/Decode: Guide to URL Percent-Encoding

Spaces, &, = and special characters in URLs cause errors. Learn how to encode them correctly with percent-encoding.

URL Encode/Decode Read >

UTILITY

Hash Generator: Complete Guide to Cryptographic Hashes

Hashes are unique digital fingerprints of data. Learn how MD5, SHA-256 and SHA-512 work, and when to use each.

Hash Generator Read >

UTILITY

Regex Tester: Guide to Regular Expressions with Real-Time Testing

Regex are powerful but complex. Test your patterns in real time with visual highlighting, capture groups and flags.

Regex Tester Read >