I'm trying to fetch a nonexistent (unresolvable hostname) page using wget. I expect it to fail, but it does not.
Here is a transcript
[mark@cn ~]$ cat /etc/resolv.conf ; google public nameserver 8.8.8.8 nameserver 8.8.4.4 [mark@cn ~]$ host nonexistent.example.com Host nonexistent.example.com not found: 3(NXDOMAIN) [mark@cn ~]$ wget -O - http://nonexistent.example.com/ --2010-09-05 22:12:09-- http://nonexistent.example.com/ Resolving nonexistent.example.com... 205.178.189.131 Connecting to nonexistent.example.com|205.178.189.131|:80... connected. HTTP request sent, awaiting response... 301 Moved Permanently Location: http://127.0.0.1 [following] --2010-09-05 22:12:09-- http://127.0.0.1/ Connecting to 127.0.0.1:80... connected. HTTP request sent, awaiting response... 200 OK Length: 524 [text/html] Saving to: `STDOUT' 0% [ ] 0 --.-K/s (some HTML that my local Apache serves) 100%[======================================>] 524 --.-K/s in 0s 2010-09-05 22:12:09 (62.5 MB/s) - `-' saved [524/524]
Why is this happening? Any ideas?
OS: Centos 5.5 x86_64 Network: cloudnext dedicated virtual servers
I'm asking because I've tried the same in Python code and something similar is happening. Something fishy is going on and I can't quite figure out what.
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Did you maybe leave out the part of your
resolv.confwhere your search domain(s) are listed?If at least one of your search domains has wildcard entries (or your server FQDN domain), then what
wgetreally resolves, isnonexistent.example.com.your.domain.com.. This probably leads to a web server that is configured to redirect the client to localhost, if it gets a query for an unknown VHost.The proper way to fix this in my opinion would be, to not use wildcard domains or at least not to use these as search domains. If infact your server's FQDN is in a wildcard domain, you could work around the problem by putting this in your
resolv.conf:options ndots:1 search .MarkR : Spot on. It was using my host's official host name as a search path, and THEIR DNS had a dodgy wildcard entry. Thanks for your help.From al -
I suspect it's because Google DNS is returning an answer for virtually all requests. OpenDNS is similar as well... the idea is that they can redirect unknown host requests elsewhere for correction (*cough) and ad revenue (*cough).
What happens if you change the DNS servers to something else? Like 4.2.2.2?
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ErikA : Yup, a.k.a. NXDOMAIN hijacking. All too common of a practice, IMHO.Phil Ross : Google Public DNS always returns an NXDOMAIN response for records that don't exist - see http://code.google.com/speed/public-dns/faq.html#nxdomainsMikey B : Anyone remember sitefinder? =PMarkR : Thanks for your reply, but Google Public DNS always returns an NXDOMAIN, as my transcript showed.From Mikey B
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