Technical Troubleshooting

Clearing (flushing) your DNS cache resolves issues where you can't access a website that recently changed IPs.

Windows: Open Command Prompt as Admin and run ipconfig /flushdns.
macOS: Open Terminal and run sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder.
Linux: Run sudo systemd-resolve --flush-caches.

NAT is a method used by routers to map multiple local private IP addresses to a single public IP address before transferring the information to the internet. It allows all devices in your home (phones, laptops, TV) to share one internet connection from your ISP.

Port Forwarding (or mapping) directs traffic coming from the internet on a specific port to a specific device on your local network. It is required if you want to host a game server, web server, or security camera at home so people outside your Wi-Fi can access it.

TCP (Transmission Control Protocol) is reliable; it ensures all data arrives in order and error-free (used for web browsing, email). UDP (User Datagram Protocol) is faster but unreliable; it sends data without checking if it arrived (used for streaming, gaming, VoIP) where speed matters more than perfection.

Bandwidth (download speed) and Latency (ping) are different. You can have a "wide pipe" (fast download) but a "long pipe" (high ping). High ping is usually caused by physical distance to the server, routing inefficiencies, or network congestion, even if your fiber connection supports high speeds.

CIDR (Classless Inter-Domain Routing) is a compact method for representing IP addresses and their routing prefix. It uses the format IP/Prefix, where the prefix tells you how many bits are used for the network ID. For example, 192.168.1.0/24 means the first 24 bits are the network, leaving 256 addresses for hosts.

When you update DNS records for a domain, the changes don't update instantly worldwide. It takes time (up to 48 hours) for the new information to spread to all DNS servers globally. This delay is called DNS propagation. You can check the status using our DNS Lookup Tool.

Subnet masks must consist of a continuous string of binary '1's followed by continuous '0's. 255.255.255.0 in binary is 11111111.11111111.11111111.00000000, which is valid. A value like 255.255.255.1 would be ...00000001, which breaks the continuity rule and is invalid.

Open a terminal and run the command ifconfig or ip link show. Look for the value next to ether or HWaddr. It will look like 00:11:22:33:44:55.

Packet loss occurs when data packets traveling across a network fail to reach their destination. It causes lag in games and stuttering in video calls. It is typically caused by network congestion, faulty hardware (cables/routers), or Wi-Fi interference.

MTU is the largest size of a data packet (in bytes) that can be transmitted over a network. The standard internet MTU is 1500 bytes. If a packet is larger than the MTU, it must be fragmented (broken up), which slows down the connection. Optimization involves finding the largest MTU your connection supports without fragmentation.

This is an APIPA (Automatic Private IP Addressing) address. It means your computer tried to contact the DHCP server (router) to get an IP address but failed (timed out). It assigned itself this random address to allow local communication, but you won't have internet access.

Traceroute is a diagnostic tool that tracks the path (hops) a packet takes from your computer to a destination server. It shows every router it passes through and the time it takes. It helps identify exactly where a connection is breaking or slowing down.

There are 65,535 TCP ports and 65,535 UDP ports available for use. Ports 0-1023 are 'System Ports' (reserved for standard services like HTTP/80), 1024-49151 are 'User Ports', and 49152-65535 are 'Dynamic/Private Ports'.

IPv6 tunneling is a mechanism that encapsulates IPv6 packets within IPv4 packets to allow them to travel across an IPv4-only network infrastructure. This allows devices to use the modern IPv6 protocol even if the intermediate internet backbone hasn't fully upgraded yet.

A sitemap index acts as a container for other sitemaps. It is essential for large websites with over 50,000 URLs or files larger than 50MB. Our Sitemap Checker can detect these indexes and allow you to drill down into each sub-sitemap for detailed SEO validation.

XML sitemaps must start with on the absolute first line. If there is even one empty space or line before this tag, search engines and our Validator will throw a 'Missing XML Declaration' error. Always ensure your sitemap starts on line 1, character 1.

Our Universal Markdown Converter supports PDF, DOCX, HTML, XML, JSON, and CSV. It extracts the semantic structure of these documents and maps them to clean Markdown. You can also paste a Webpage URL to extract the main article content instantly.

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