Every internet user has encountered a website being down, an app not working, or even a browser failing to connect to the internet. Every day, thousands of users like you use Downdetector® to report real issues for websites and apps, but the outage you’re experiencing is often more complicated than it seems. We’re here to identify the major points of failure for the internet so you can understand what is happening and how long you might expect services to be down. Read on to find out what’s really going on during these incidents and how one service can cause critical failures across the internet.
What a large outage or incident looks like
Over the past few years, the internet has been hobbled by major outages. Some of these incidents lasted for hours (and even days) and prevented people from accessing online services like websites, streaming video platforms, social media, mobile apps, ATMs, emergency services, and more.
On the best of days, you can simply log onto the internet with the ease of clicking open a browser. However, the internet is a complex web of interconnected parts that exist on physical servers around the world. Often, when one part of the internet has an issue, it cascades to other services and companies that depend on that particular component. For example, if your internet service provider (ISP) blinks out, you might think that the site you were just visiting is down, while others using a different ISP can use the site just fine. Similarly, when you can’t access a website or app you want to use, the root cause might not be the app or website, like when an AWS incident took out Netflix in April 2021.
These five potential points of failure can take down the internet and online services
Internet service providers (ISPs) and mobile operators connect you to the web
The simplest internet outage to understand occurs when an ISP or mobile operator goes down or can’t be accessed. This can happen for many reasons, including a severed fiber line or a power outage taking out a local cell tower. When an ISP or mobile network suffers an outage, the internet still functions correctly, but your computer or device won’t be able to access it. This is frustrating and also makes it complicated to identify what the problem even is.
One way to figure out if your ISP or mobile provider is down is to try to access the internet from a different network (if you’re on mobile, try your computer; if you’re on your computer, try your mobile network). If the site is accessible on the other device, you may have a carrier or ISP outage. Check with your ISP on Downdetector or social media to see if they are aware of the problem, then know they are hard at work on fixing it. Usually these types of outages are resolved within a couple of hours.
Fixed Broadband ISPs
ISPs can go down due to hardware failures, severed cable lines, natural disasters, human error, or even network cyberattacks. These are often contained to small local areas, but some ISP incidents have been nationwide.
Consumers and businesses both rely on ISPs to offer and access internet-based services. When a specific ISP does go down, cities, banks, businesses, online gaming, point-of-sale devices, and more that use single ISPs can all face outages because those services may depend on specific ISP access to the internet. But that doesn’t mean everything goes down in your area if one ISP goes down in an area; if other ISPs are operational, they’ll be able to connect to the internet. This is why some businesses use multiple ISPs to insure against outages.
If you think your ISP may be down, check Downdetector on your phone for real-time incident reports by users in your area. For those who are comfortable with running terminal commands, you can run `mtr -rn 8.8.8.8` to see which hop within your connection may be having issues.
Mobile operators
You’ve probably seen a cell tower in your neighborhood. Mobile networks connect your device to the internet using radio waves collected by those towers and other infrastructure. When a mobile network goes down, either the equipment sending or receiving radio waves is having an issue or the network that equipment connects to is having an issue. This may be contained as a local issue with a single mobile deployment, but mobile networks aren’t immune from larger incidents. Though more rare, mobile outages can be caused by natural disasters, faulty equipment, or human error.
For you, a mobile outage means you may not be able to text or call from your mobile network until the problem is resolved. If you think your mobile operator may be down, use your computer to check Downdetector for real-time incident reports by users in your area.
Content delivery networks (CDNs) deliver critical content
CDNs allow content (like images, videos, and other critical parts of websites) to be stored physically closer to you using networks of point of presence servers (POPs) around the world. Websites and apps use CDNs to dramatically speed up and stabilize your experience, because the information has to travel less distance and bypass potential bottlenecks on the internet. In addition, many ISPs and mobile operators have CDN POPs within their own networks, further reducing the distance a request has to travel to be fulfilled.
CDNs are a vital part of modern internet infrastructure and are particularly helpful when a service needs to respond quickly to increased demand. Examples include a surge in online shopping on Cyber Monday or a rush of viewers streaming the next episode of that most popular TV show. Still, CDNs can experience incidents that impact their reliability. Since these are consolidation points for internet traffic, CDN outages can have huge effects on a wide range of internet services all at once. When CDNs go down, sites aren’t able to be served and apps aren’t able to receive the content stored on these networks. These failures make the sites and services appear to be down. CDN failures can stem from coding bugs or a cyberattack. CDN issues are often difficult to diagnose since they operate behind the scenes and cover specific geographies. This means a CDN network can work in one part of the world, while other parts experience a blanket outage for all the businesses that depend on it.
One indicator that you might be dealing with a CDN outage is if a group of sites and services that rely on one CDN provider are all showing issues on Downdetector in your area, as you can see on the image above related to the Akamai service outage of June 2021. We will often flag CDN outages on Downdetector with a banner to show how trending incidents may be connected.
Domain Name System (DNS) and Border Gateway Protocol (BGP) direct internet traffic
DNS and BGP are two systems that serve as the foundation for the global internet. You could say that DNS defines the addresses to which packets of information need to navigate and BGP effectively defines the roads of the internet. Without directions from DNS and BGP, the internet would not function. DNS and BGP issues can be contained or they can cause global internet outages.
Domain Name System (DNS)
DNS provides the connection between human names and network addresses — every website has a domain name (like speedtest.net), which DNS translates to a string of numbers that forms the IP address for every site you visit. Without DNS, your browser won’t be able to determine where to send a request to, like attempting to drive to a business without being able to find their address.
DNS incidents can either be caused by a bad DNS record which sends traffic to the wrong location or if a large DNS provider has issues responding to requests. Because DNS servers are so important, there are many redundancies to prevent global failure — but they can go down due to cyber attacks, power incidents, or human error.
If the DNS issue is on your equipment, it can sometimes be resolved by restarting your router and/or modem, clearing your device’s DNS cache, or even switching browsers. Larger DNS issues can be identified by querying a server (if you feel confident doing so), and you can also go to Downdetector to see if it’s a larger issue impacting many people. Visitors to Downdetector will often leave a comment if they’ve run a query and found a DNS issue.
Border Gateway Protocol (BGP)
BGP is the routing system for the internet, receiving routing information from other networks on the internet and using Autonomous Systems (AS) to find the fastest and most efficient path to connect your device to the destination network. BGP isn’t centralized or controlled by any party, it’s up to internet providers to provide accurate and trustworthy information to other peer networks. BGP-related outages often are due to bad routing information being shared across the internet, which causes data to be sent to incorrect networks.
BGP issues can be harder to identify, because when BGP goes down, the route to a particular network doesn’t appear to exist even if it’s there — and information can’t automatically update because everything is decentralized. Visit Downdetector to troubleshoot your outage. You can learn more about whether the incident is caused by a BGP issue by checking the comments. Because of the decentralized nature of these outages, the issue may take a while to resolve. Be prepared to maybe take a walk or find something to do until the engineers work it all out.
Services and their Application Programming Interfaces (API) direct programs communicating
The final type of widespread incident types on our list involves service failures. When services go down, they may impact other applications that communicate and rely upon them through an API. An API is an interface that enables two or more programs to communicate together. For example, a weather app on your mobile device may fetch forecast info from a weather station’s API. If that API is down, your weather app may display a blank content box or not work at all.
APIs include everything from applications like Google Maps interfacing with GPS data to get you to a destination, posting a photo to Instagram or Twitter with the your device’s camera app, sending a GIF from Giphy on your messaging app, completing a transaction on a commerce site with a payment app like PayPal, and security protocol programs like Auth0 or OneLogin that provide single sign-on services for additional security to your logins.
With many companies increasingly relying on external services for payment services (Square and Stripe), security measures (OneLogin and Google Safe Browsing), programming queries (Javascript and Python), storage (Dropbox and Google Drive), and many other different service APIs like Spotify, incidents at these types of services can have huge impacts across the internet.
Diagnosing a problem caused by a service or their API isn’t straightforward. Often, service issues stem from a coding error that occurs that doesn’t allow the program to communicate information to the service’s API. Engineers at the services monitor service health carefully, but these errors may only occur in edge cases, or for a small subset of users. Even if a service doesn’t have a large amount of reports on Downdetector, check the comments to see if anyone else is reporting a similar issue to yours.
Downdetector is your first line of support during a widespread incident
Do you think your service or internet is down? First, check your device or router and restart those. If that doesn’t work, go to Downdetector to report your incident with the internet or service you’re trying to reach and see if other users are reporting the same issues you are, or if there are other root causes that may be contributing to an incident you’re experiencing. Remember, while Downdetector can detect widespread issues, it does not diagnose them, so after logging your issue on Downdetector, check in with the service you’re having trouble with to see if they have any error reports.
Having issues with the internet can be a huge headache, so we hope this article helps you better understand what’s going on with your internet experience. Do you want to stay on top of issues that might be affecting your internet experience? Download the Downdetector app for iOS or Android.
