Flush The Cache – Troubleshooting Internet Access Issues
Having problem accessing certain websites that work perfectly fine before? Cannot login to your bank’s online portal which worked fine the day before? You may be suffering from the wrath of the corrupted cache problem. Following are standard procedures to resolve the problem quickly.
Cause Of The Problem
When the access information that is saved on your computer no longer matches the ones you obtained online, your computer will react in funny ways and not allowing you to login properly to your favourite websites. This is actually a common problem whenever the underlying infrastructure of the servers hosting or serving the websites you need access to have changed. Anyone who has encountered the logged in but not logged in problem with their online banking service knows how frustrated this can be.
There are 3 types of cache stored on your computer. Not one, not two, but three different kinds. You need to clear all three kinds of cache on your computer to allow it to re-establish proper connection with your secure websites.
The Browser Cache
Depending on the browser you are using, it cache (i.e. temporarily storing things locally) from part of the website, secret handshakes to even video on your computer. The purpose of the cache is to make things run smoothly at your end. It works most of the time until the website no longer works the same way as before. At this point you need to clear the cache.
For secure connections, notice that it is likely you need to clear both temp files and cookies for the specific website you have trouble connecting to. Not all browsers support cache clearing on specific website data. Thus what you need to do exactly depends on the browser you are using.
Following are a list of common browsers and their official cache clearing methods.
Internet Explorer
How to delete your browsing history in Internet Explorer 9
Delete temporary Internet files – Windows – Microsoft
Firefox
How to clear the Firefox cache Firefox Help – Mozilla Support
Chrome
Delete your cache and other browser data – Chrome Help
Safari
Safari 5.1 (OS X Lion)- Empty the cache – Support – Apple
Safari 6 (OS X Mountain Lion)- Remove cookies and other
If you prefer a friend version of the instructions, you can read the article How Do I Clear My Browser’s Cache from About.com
The Java Cache
Java is a requirement in almost all instances of secure connections. To speed things up, Java store many things from the websites locally on your computer to improve performance. That also means you will have many things not working if there is a change to the underlying structure of the secure connection.
Specifically, java is used to execute mini programs behind many websites. These mini programs are called Java scripts. These scripts, as you may have guessed, are cached locally on your computer. When a website changes its scripts, most of the time the Java engine on your computer would know that it should update the script on your computer. Sometimes, however, the script is stuck because it is corrupted or time stamped incorrectly.
When the java scripts on your computer are not the correct ones the website required, the website would not function properly. When this happens you need to flush the Java cache.
There is only one official source of information for Java. Following is the instruction to clear the Java cache.
How do I clear the Java cache?
The DNS Cache
DNS stands for Domain Name Server. All websites on the internet are presented by their IP addresses which are a sequence of numbers. The name you use to access the websites are add-on service provided by the DNS to make the internet more user friendly. Think of DNS as a phone book to the internet will give you a better idea what it is.
You can read my other article to learn more about DNS and the trick to potentially speed up your internet access.
When the website you need to access to has changed its underlying IP address, the DNS cache you have on your computer will be pointing to the wrong computer server on the internet. During the time your ISP and your computer not aligned with the correct DNS records, your computer will not be able to access the website in question.
Normally, your computer will receive an update of the DNS changes within hours from the time the website itself has the confirmed change. The new information is propagated to all the DNS across the internet. It may take up to 48 hours for some remotely located DNS to receive the updated information and accept the changes.
All these automatic update sounds magical, isn’t it? It is magical indeed when it is working fine.
The problem, however, is that some computers, especially the older computers with earlier version of Windows and Apple OS, do not really handle the job of updating the DNS cache, which is stored locally, correctly. It often takes a reboot of these computers before they can grab the updated version of the DNS records from your Internet Service Provider (ISP).
In case your computer is one of those computers that simply refuse to update its DNS properly, you may even need to flush the DNS cache manually so that a new copy can be obtained from the ISP.
Following are instructions from Apple and Microsoft on resetting DNS data on your computers.
Apple Computer
How To Reset The DNS Cache on Apple OS X
Windows
DNS FAQ (the question "How can I clear the DNS cache?" is the last question there)
Summary
Flushing the caches from time to time is a great idea to keep your computer functioning properly if you need access to the Internet all the time. You may not know what to do last time when you could not access certain websites. Now you know what to do.