Are you talking about such redirect pages that send you to search results rather than returning a DNS error?
If so, you could simply try to request a domain that's not existing and see whether you're redirected?
Or are we talking about hijacking used to redirect requests through some proxy, e.g. to recompress or filter content?
For the latter, you can try the following:
- Open a terminal window or command prompt (depending on your operating system).
- Ping the domain you think is redirected, e.g.
- Write down the IP that is shown.
From here on, you've got multiple possibilities. You can try one after the other or skip the first one as well:
Compare returned IP adresses
- Go to http://web-sniffer.net and input the domain as a standard address (the domain doesn't have to run a http server at all; it just has to be reachable from the internet; without a server running this might take quite a bit). In my example it would be
- Select the request type
HEAD (you don't need any document content etc.).
- Submit and check the results. Under "HTTP Request Header" the first line should be telling you the IP.
- Compare this IP with the one you've written down earlier. If they're completely different, it's possible your ISP spoofs the DNS request, but it's also possible that the difference is perfectly legit (e.g. due to the target domain being served by multiple different IPs/hosts).
Determine the location/owner behind an IP
- Use the IP you've written down first (using the
ping command) and use a service such as http://www.ip2location.com/ to determine the domain name and possibly owner. If these doesn't fit the actual company you expected (e.g. the IP belongs to your ISP rather than a foreign company), it's quite likely something is being weird.