Stop RV082 acting as DNS server?

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Jul 26th, 2013
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We have a RV082 that we're using soley for routing and no other services (firewall is disabled). For some reason you can query a DNS server on it even though we have never set a DNS server address for it to use. I'm guessing that it has some hard-coded DNS system to use with the System Management > Daignostic > DNS Name Lookup utility. Because you can query this DNS service from outside the router, this actually gets flagged by our security scanners as a DNS vulnerability. Is there no way to disable this DNS server?

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Tom Watts Fri, 07/26/2013 - 11:40
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Hi IT, if I had to make a guess, the router have have a DNS proxy feature enabled. Try to see if you can find a DNS proxy enabled as that could cause this symptom.



-Tom
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Tom Watts Fri, 07/26/2013 - 13:46
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Hi It, here is an excerpt from the product documentation. Are you using the DHCP from the router? Did you specify any DNS value on the router? It seems by default the router acts as a DNS proxy (using your WAN setting to feed DNS to the LAN client). Keeping the value at 0.0.0.0 makes the router service as a DNS proxy.


DNS (used for DHCP Server only)

Optionally, enter the IP address of a

DNS Server

. You also can enter a secondary

DNS server. Specifying a DNS server can provide quicker access than using a

DNS server that is dynamically assigned through the WAN settings. You can keep

the default setting of 0.0.0.0 to use a dynamically assigned DNS server.




-Tom
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I.T. Registrations Fri, 07/26/2013 - 14:36
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We are not using DHCP (either for LAN or WAN), but the WAN DNS was set to 0.0.0.0. We set it to 127.0.0.1 and it began refusing DNS queries, solving our problem.


Thanks for you help with this.


I'm still curious to know what DNS server it was using to query when the DNS was set to 0.0.0.0.

Tom Watts Fri, 07/26/2013 - 15:56
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your isp dns or whatever dns specified on the WAN so it is really weird. Anything connecting through the WAN port could constitute the DNS server.



-Tom
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