Re: Content filtering not working; ipconfig shows two dns addresses - Page 2

dagny · ‎08-18-2015

After many years of successful use, recently I noticed content filtering wasn't working. Multiple PCs in my home are affected.

The PCs are configured to use DHCP. Running ipconfig /all on a PC shows:

DNS Servers . . . . . . . . . . . : 192.168.0.1
24.205.224.36

192.168.0.1 is my router and 24.205.224.36 is the DNS provided by my ISP, despite the fact that I have changed my router settings to use the OpenDNS addresses.

I don't know why the ISP DNS server address is listed when the PC's are configured to use DHCP. I seem to recall that it was always listed in the past, but content filtering still worked. I assumed it was there only as a backup, even though it always troubled me as to why it was there.

My dynamic IP is correct on the OpenDNS site and is being periodically updated using the Marcs updater.

If I change the PC's network adapter TCP/IP Properties to use the OpenDNS servers (and confirmed with ipconfig), content filtering works.

I've provided the output from some debugging suggestions I've seen from other posts:

Output of commands entered when DHCP is configured for IP and DNS:

C:\Windows\System32>nslookup -type=txt debug.opendns.com.
Server: my.router
Address: 192.168.0.1

DNS request timed out.
timeout was 2 seconds.
*** Request to my.router timed-out

C:\Windows\System32>nslookup -type=txt which.opendns.com. 208.67.220.220
Server: resolver2.opendns.com
Address: 208.67.220.220

Non-authoritative answer:
which.opendns.com text =

"9.lax"

Output of commands when DHCP for IP address, but OpenDNS addresses are manually entered:

C:\Windows\System32>nslookup -type=txt debug.opendns.com.
Server: resolver1.opendns.com
Address: 208.67.222.222

Non-authoritative answer:
debug.opendns.com text =

"server 1.lax"
debug.opendns.com text =

"flags 20 0 72 1950000902000081040"
debug.opendns.com text =

"originid 35380373"
debug.opendns.com text =

"actype 2"
debug.opendns.com text =

"bundle 7798509"
debug.opendns.com text =

"source 96.40.141.137:52080"

C:\Windows\System32>nslookup -type=txt which.opendns.com. 208.67.220.220
Server: resolver2.opendns.com
Address: 208.67.220.220

Non-authoritative answer:
which.opendns.com text =

"1.lax"

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I've tried ipconfig /flushdns and I've deleted and added my network back, but no change.

Questions:

Why is content filtering not working with the standard DHCP setup for my PCs?
Why does the ISP DNS address appear in the output of the ipconfig/all? Is that normal?
What am I doing wrong?

Appreciate any help. Thanks.

dagny · ‎08-21-2015

Since my router's address is already listed first in the ipconfig output, doesn't that mean addresses will be resolved by the router first?

In any case, it would seem that my router is acting inconsistently so I'll upgrade the firmware.

Thanks!

mattwilson9090 · ‎08-21-2015

It generally means that, or more precisely, it's the first preference, but there are any number of reasons why other addresses could be used, which is why you were having the inconsistent results in the first place. At least with this configuration you know that all of your searches will ultimately be resolved by OpenDNS, which is the primary goal.