Should I switch my current DNS resolver?
If you are just a regular Internet user (not self-hosting anything), and you are currently using your ISP’s DNS resolver, I would switch to a 3rd party DNS service (e.g., Cloudflare).
However if you are self-hosting anything (e.g., email), then I would opt for running my own DNS resolver for reliability.
Here are my opinions on the three typical ways to get DNS.
ISP DNS Resolver: usually OK performance / no privacy
- Works out-of-the-box with your Internet service.
- Since you are using servers they control, always assume your ISP is logging your DNS requests (no privacy).
- Sometimes an ISP actually has worse DNS resolvers (slower, less secure) than a 3rd party DNS service.
- I used to make use of my ISP’s DNS resolvers. They would occasionally go down every few months. It made it look like the Internet was down, but it was just their DNS resolvers that were down, which caused software to fail since they could not resolve domains to connect to services.
- Some ISPs will redirect you to their own online search engine, if the domain you are looking for does not exist. That is real tacky. They should just give the standard DNS error response, instead of – effectively – hijacking your DNS service.
Third-Party DNS Resolver (e.g., Cloudflare, OpenDNS): good-to-excellent performance / potentially less private
- Can be faster than your ISP’s DNS resolvers. This is due to 3rd party DNS services having a very large network infrastructure. They can handle large amounts of traffic with ease.
- Cloudflare does support DNS-over-TLS. However this is just encrypting your connection to Cloudflare. When Cloudflare retrieves the DNS records for you – assuming they do not have a cached copy – that connection of theirs is unencrypted. This means the DNS records Cloudflare gets for you can be manipulated by a 3rd party, outside of Cloudflare’s control.
- Encrypting your DNS does not prevent your ISP from seeing what domains you are going to, if the web-server you are connecting to does not support both the TLS 1.3 protocol and the ESNI extension. This is due to the fact the SNI (Server Name Identification) gets sent from the web-server in plain text. With this information, your ISP can effectively see which domains you are visiting, regardless if your DNS is encrypted via Cloudflare or another 3rd party service.
- Unless you are using a VPN service, your ISP will still have to route your connection to the website (they can see the web-server’s IP address). This may give away where you are going on the Internet, even if your ISP cannot read your DNS queries.
- There are some free public DNS resolvers, run by volunteers (read: no large corporations), who claim they do not log your domain lookups. Just like I mentioned before, you must take their word for it.
Self-Hosted DNS Resolver (e.g., Unbound DNS server): OK-to-good performance / potentially more private
- Useful if you want to have reliable lookups, since you are cutting out the middle-man handling your DNS requests (you are going directly to the source, instead of having someone else do it for you).
- If you are self-hosting web services (e.g., web and email), it is recommended to run your own DNS resolver. While not necessary, this will help prevent interruptions to your services.
- While there is no worry about the DNS resolver keeping logs (you are running it, after all), there still is the possibility of your ISP and/or other entities sniffing your DNS lookups and keeping a log that way. This is because DNS is inherently insecure (not encrypted).
- Unbound runs on many different operating systems (e.g., FreeBSD, OpenBSD, NetBSD, MacOS, Linux and Microsoft Windows).
- Unbound does require some knowledge of DNS to be setup properly. Users who have little to no experience with DNS servers may find setting up Unbound to be difficult.
- Something to keep in mind. When doing your own DNS lookups, usually you are contacting the Root DNS servers, domain TLD nameservers, and of course one of the domain’s nameservers using your public IP address from your ISP. This means all three of those services may log your IP address when doing lookups.
- For example, if I lookup my domain computerlagoon.com via Unbound, it will first ask a Root DNS server for a nameserver belonging to the .com TLD. From there it will ask one of the TLD’s nameservers for one of my nameservers to get the webserver’s IP address.
- There is a very good chance the .com TLD nameserver, run by Verisign, is logging domain lookups. This means someone, somewhere is more than likely logging your lookups (associating your lookups with your IP) even if you opt to self-host your own DNS resolver.
|Easiest out-of-the-box solution | best for people who just want things to work
|ISP DNS resolver
|Best performance | good for people who want more performance than what their ISP provides
|3rd-party DNS (e.g., Cloudflare, 188.8.131.52)
|Best reliability | best for people who self-host web services (e.g., email)
|self-hosted solution (e.g., Unbound DNS server)
Posted in Computers, Internet and Servers, Operating Systems, Security
A while back, I read on a website that the Command Prompt on the NT-based versions of Windows are somehow from MS-DOS. This is a myth.
While the Command Prompt (cmd.exe) does copy the commands from the MS-DOS (command.com) command line, this does not make the Command Prompt in Windows NT in any way, shape, or form, related to MS-DOS.
For example, I could write a C#.Net console application that mimics Linux bash commands, but that would not make my application “bash”. I am just mimicking the commands from bash. The same applies for the Command Prompt on the versions of Windows NT. The Command Prompt may use the same commands as the MS-DOS one, but that does not make it DOS.
Here is a bit of information some people may find interesting.
32-bit Windows NT operating systems (e.g., WinXP, WinVista) can run DOS programs due to having a built-in 16-bit “NT Virtual Dos Machine” otherwise known as NTVDM. This allows people to run DOS programs (even full-screen ones) without much problems.
However the 64-bit versions of Windows do not have NTVDM. For the 64-bit Windows operating systems, an emulator (e.g., DOSBox) is required to run DOS programs.
Posted in Computers, Operating Systems, Software
Many people use online services to generate secure passwords.
web browser add-ons – Many people use web browser add-ons (such as Ad-blockers) for their everyday browsing. What most people are unaware of is that many of these add-ons have permissions that allow the add-on to view the content of the web pages the user is viewing.
Would only using open-source browser add-ons be a safe option? Well open-source add-ons would definitely lower the chance that someone would get away with spying on you. However open-source projects do not have a spotless security track record either. There is still some risk.
Even Mozilla themselves warn about this problem with web browser add-ons (also called extensions).
Update 12/05/2019: Here is another example of what I am talking about (https://www.zdnet.com/article/mozilla-removes-avast-and-avg-extensions-from-add-on-portal-over-snooping-claims/).
While Windows-based systems have more malware available for them, Mac and Linux are not completely in the clear either. As more people start using these other OSes, more and more malware will be created for them.
Android (the very popular Linux OS used on smartphones all over the world) has a good number of malware created for it.
surveillance software – Some people have to use computers provided by their employer. Some employers put surveillance software onto their computers to track and monitor their employees’ usage of those systems.
Summary: Assume any work computer is being tracked. Always use your own personal computer for anything non-work related.
So does this mean that I should never use any online password generators at all?
Posted in Android, Computers, Internet and Servers, Operating Systems, Programming, Security, Software
To access the Internet, your Internet Service Provider (ISP) assigns you an IP address. This allows you to talk to other computers on the Internet. Most people do not even think about their IP address they have been assigned, much less what type of IP address they have.
There are two kinds of IP addresses, static and dynamic.
Static addresses never change on you. Even after many months (or even years), the IP address you have been assigned stays the same. Dynamic addresses, on the other hand, usually change every few weeks (or months). Most people probably are assigned a dynamic address for a month or two at a time.
Pros of Static Addresses
- Allows you to easily host web services (e.g., email, DNS, websites)
- Helps prevent websites from mistaking you for being an abusive user. This is because when using a dynamic IP address, someone else had previously used that address, and may have been committing abusive behavior online. However, when using a static address, you (and whoever else has access) are the only ones using your address.
- Allows for a more stable VPN connection, because a dynamic IP may change any moment, and this will break the VPN connection.
Cons of Static Addresses
- ISPs usually require you to purchase a “business” Internet package to be able to obtain a static IP. This may cost more money per month than a typical residential Internet package.
- Everywhere you go online can be easily tracked, since you use the same IP address everywhere you go online (a VPN can help with this problem).
- If someone starts constantly abusing your IP address (e.g., DDoS attack), you likely will not be able to quickly request a new static IP address from the ISP.
- If you have a unique host-name assigned to your static IP (necessary to host an email server), you will have less privacy than someone who has a typical residential, dynamic IP address without a custom host-name.
Pros of Dynamic Addresses
- Usually can easily change your assigned IP address (helpful to stop someone who is abusing your computers; e.g. DDoS attack).
- Since your IP address is “generic” (used by several other people), you are more anonymous than a static IP constantly browsing the web.
Cons of Dynamic Addresses
- Hosting web services will not be very stable, since you are using a dynamic IP address that may change anytime on you (note: using a “dynamic IP” DNS service is more of a “jury-rig” than a proper solution).
- Some web services may think you are a trouble-maker, since someone else may have had your IP address previously and used it to abuse web services.
- ISPs may deny you the privilege of running any web services unless you have a “business”-grade Internet package (most people using a dynamic IP do not have a business account at their ISP).
Posted in Computers, Internet and Servers, Operating Systems, Security, VPN