How can one avoid a 404 redirect from an ISP?

I believe some of the subdomains of stackexchange just went down. This event reminded me of a question I've been meaning to ask. As stated, "How can one avoid a 404 redirect from an ISP?" For example, I type in the Webap开发者_运维知识库ps url right now and I can't get to it; however, instead of showing me what is probably a very useful 404 page from stackexchange, my ISP (*cough, Comcast) redirects me to their search engine. Is there anyway to circumvent this behavior whilst still sending a 404 redirect?

I guess implicit in my question is a possible misunderstanding -- if you don't send a 404 redirect, but simply display the customized stackexchange 404 search page -- Would this break compatibility for some users, e.g. mobile users?? (I'm sure you could filter based on where a user is coming from and make the decision in real time, but I'm a noob when it comes to webservers -- my 404 is just a static page -- and I'm really asking if there's a simple fix to prevent my users from experiencing a similar headache...

First, as a clarification, a 404 isn't a redirect, its just an error code. So when you ask about "if you don't send a 404 redirect", its not really a valid question.

It sounds like what is happening is that you are using your ISPs DNS servers, and when your browser asks them something like "what is the ip address of doesntexist.example.com" (something that doesn't exist). Instead of your isp returning a "name not found" DNS response, they give you give you the ip address of their search engine. This is probably in order to drive traffic to their website under the guise of being helpful.

You can probably get rid of this by switching nameservers. Perhaps to google's 8.8.8.8 nameserver.