[ars_technician]

Did you even read his comment?

"dig @www.facebook.com news.ycombinator.com" does not use the ISP's DNS servers at all. It sends a DNS query to Facebook for Google, which should normally fail. His ISP hijacks the request and provides a response. In this scenario, the advice in your comment is pointless because they will hijack requests whether they are directly to authoritative servers or if they are to recursive servers.

[gwu78]

Yes, I read his comment.

""dig @www.facebook.com news.ycombinator.com" does not use the ISP's DNS servers at all"

Incorrect. The program he's using, dig, has to look up the numbers for facebook.com's authoritative servers first. And what DNS servers do you think it uses to do that? The defaults he has set: his ISP's.

"It sends a DNS query to Facebook for Google."

Incorrect again.

The "advice" I provided is not pointless. I would not provide pointless suggestions.

[gwu78]

"What aren't you getting?"

I am glad you asked. I am not getting what it is you are trying to say. I also do not get why you keep mentioning Google.

"The query for Facebooks server may use the ISPs DNS server, but that's not the problem."

Why is that not the problem?

If you query the ISP's DNS servers, then the ISP can send you bogus answers. By giving you bogus answer they can redirect your HTTP requests, which enables them to insert ads, among other things. I presume you would want to avoid this. I gave examples how you could do that. One way is to run your own recursive DNS server on 127.0.0.1. Another is to only query the proper authoritative servers.

Shaw uses a "DNS Redirect service". Customers can opt out.

https://community.shaw.ca/docs/DOC-1218

Even if a customer does not disable this "service", I believe Shaw will not interfere with packets sent to remote DNS servers other than Shaw's.

In any event, the reason I commented on this was because (unless the customer has changed his defaults)

dig @www.facebook.com news.ycombinator.com

sends queries to Shaw's DNS servers. So stop doing this.

Unless the customer opts out, these queries are going to get redirected.

If you wanted to test your theory (that Shaw is redirecting every DNS packet sent by evey customer, even ones not using Shaw's DNS servers), then the above invocation of dig will not test this. It sends queries to the Shaw DNS servers. Stop doing that.

Why does it send queries to Shaw's DNS servers? From the dig(1) manpage:

"SIMPLE USAGE A typical invocation of dig looks like:

            dig @server name type

       where:

       server
           is the name or IP address of the name server to query. This can be
           an IPv4 address in dotted-decimal notation or an IPv6 address in
           colon-delimited notation. When the supplied server argument is a
           hostname, dig resolves that name before querying that name server.
           If no server argument is provided, dig consults /etc/resolv.conf
           and queries the name servers listed there. The reply from the name
           server that responds is displayed.

"

If for some reason you wanted to send a query for news.ycombinator.com to the IP address for www.facebook.com (without using any recursive DNS servers like Shaw's which could give you bogus answers), then

dig +norecurse @31.13.75.17 news.ycombinator.com

would be the appropriate way to do it, assuming you choose to use dig.

[aendruk]

Thanks for the explanation. Would you interpret these results as supporting evidence of my claim?

  $ dig +short chaos txt version.bind @31.13.75.17     
  "PowerDNS Recursor 3.5.3 $Id$"

This happens despite having opted out via the form you mentioned.