Is there anything on a computer or a router that prevents a hacker from doing a DoS on you.

So let's say that you are going to https://www.google.com/. When you enter that in the search bar, it sends a GET request to the Google's servers. Google returns the Get request with a series of packets which would make up the website. What if, instead of one series of packets, you give the computer multiple series of packets of the same website.

Is that possible, or would the computer, or router, stop that malicious attack. If it were possible, what would happen to the computer?

I have a Windows 8.1 Pro computer. I have an Administrator account on it.


I am not asking if a website can attack DoS on a client machine. I am asking if another computer on the network can DoS another computer.

  • If you really feel your question isn't a duplicate, I strongly advise changing the title to be more descriptive and removing the warning at the top of your question to make that clearer. – GGMG-he-him Apr 5 '18 at 18:07
  • The response to a GET request is not a POST, those are two requests types . And most likely, the answer any webserver would give would be larger than one packet, so you'd receive a number of packets. Your computer (or router) would accept them, because it expects an answer from the webserver, but it doesn't know the size. Other than that, your question just isn't making much sense. – Teun Vink Apr 5 '18 at 18:39
  • @TeunVink instead of returning one series of Google packets, it might return more than one series. – ds_secret Apr 5 '18 at 18:42
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    @ds_secret Just to be clear, in this scenario, would it be Google that sends all these extra packets? Or are you suggesting someone else could attack using the connection to Google? – Anders Apr 5 '18 at 23:14
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    You need to make this question clearer. Are you asking if a website could perform a DoS on a client computer? – Neil Smithline Apr 6 '18 at 2:45

A DoS attack is typically easy to perform when the attacker has more computing and network resources than the victim. Being that you are using a typical consumer computer to talk to a collection of servers, the servers have both more computing power and more network resources than you. So it would be trivial for them to perform an attack. As you suggest, one way to achieve this would be simply overloading your network connection. Various timeouts and protections in place on your computer, your router, and the network of your ISP will provide some protection, but there really is no absolute protection against a foe as powerful as Google. If Google were determined, I suspect that they could take out your ISP's local infrastructure, performing a DoS on everyone in your region.

One interesting amplification DoS attack may be for Google's DNS servers to return your IP address for any request made to them (because of NAT, Google might have to return the IP address of your ISP). This would cause all of Google's DNS users to bombard your or your ISP's network. China came up with an similar attack using their so called Great Cannon. These attacks are hard to deal with because they cause innocent clients to partake in the attack, making filtering difficult.

The real prevention against these sorts of attacks is not technical (at least in the short term), but rather social and legal. Simply, this behavior would be bad for Google's business model. If they messed with their DNS server, people would stop using them. If this continued, ISPs would eventually start blocking all Google traffic and legal actions would be taken. One of the reasons that China's Great Cannon attack was so successful (it lasted weeks) is that it is supported by the government and there are no alternative ISPs. Something that is definitely not the case for Google.

  • I used Google as an example. It could as well be some hacker or some very small company. – ds_secret Apr 7 '18 at 0:20

In order to be considered part of the same TCP connection, the packets must have the correct source IP, destination IP, source port, and destination port. Packets that do not match an existing connection are ignored. Additionally, the TCP sequence numbers must be correct. If duplicate sequence numbers are received by a computer, it will drop the duplicate packets.

  • Could you modify the packets so that they have different sequence numbers? – ds_secret Apr 5 '18 at 19:01
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    While this answer is correct, it doesn't really answer the question. You can still perform a denial of service attack even when packets get dropped. – forest Apr 6 '18 at 1:02

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