“The internet is down, Is it really?”

Whenever some one says Internet is down, majority of time, the internet is perfectly fine. What the user actually means is that the incredibly complex multi stage process that is required to load a web page has broken at one specific stage.

Browsers are actually great at telling you exact what stage the issue has happened. But because most people just don’t see what they were expecting, they assume the entire network has collapsed.

Before you start tearing apart your router configurations or running packet captures, look at the specific error code. Here is what they actually mean.

ERR_NAME_NOT_RESOLVED (The “It’s Always DNS” Error)

Your browser is basically saying, “I know you want to go to google.com, but I have no idea what IP address that is.”

When you type a URL, your machine asks a DNS server to translate that name into an IP address. If the DNS server doesn’t respond, or if the record just doesn’t exist, you get this error. Your local network is probably fine. Your Wi-Fi is fine, your internet is fine. But the dns resolution is missing.

Where to look: Check your local DNS settings, flush the DNS cache, or see if the domain’s authoritative name servers are not working as they should.

ERR_CONNECTION_TIMED_OUT

Good news, The DNS is fine. This error means your computer sent out a TCP SYN packet asking to start a conversation, and… nothing happened. No rejection, no acceptance, just total silence until the browser eventually gave up trying and waiting. The browser actually sends multiple requests not just one.

From a network engineer’s perspective, this usually means packets are being actively being dropped rather than cleanly rejected. It could be a strict perimeter firewall rule blocking your IP, an upstream routing device issue, or the destination server is just not there.

ERR_CONNECTION_REFUSED

Unlike a timeout, a “refused” error is an explicit rejection. Your browser tried to connect to the server (usually port 443 for HTTPS or port 80 for HTTP), and the server immediately sent an RST (Reset) packet, saying that you are not welcome.

The good news? Your routing and DNS are perfectly fine. You reached the server. The bad news? The web service on that server (like Nginx, Apache, Caddy etc) is either crashed, not listening on that specific port, or a local server firewall is actively telling you to go away.

NET::ERR_CERT_DATE_INVALID

This is an SSL/TLS error, and it almost never has anything to do with your local network.

To establish a secure HTTPS connection, the server presents a certificate proving it is who it claims to be. These certificates have strict expiration dates. If a company forgets to renew their cert—you won’t believe how common that is, even for massive tech companies—your browser will throw a massive, scary red warning page.

It doesn’t mean you’ve been hacked; it just means the destination server you are trying to connect to has an expired certificate. 99% of time its safe to ignore the warnign and proceed, but do it at your own risk.

ERR_INTERNET_DISCONNECTED

ok, this is the one time the “internet is actually down”, not the whole internet, just internet connection at your home or office or cafe wherever you are.

Your operating system is reporting to the browser that it has no active outbound network interfaces. You aren’t connected to Wi-Fi, your Ethernet cable is unplugged, or your local router is entirely disconnected from the ISP. The browser didn’t even attempt to send a packet because it knows there is no physical or wireless path out of your machine.

This is the time when you should actively try to troubleshoot your own end of things.

Next time your browser fails to show you the expected cat videos check the exact error code.