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[FurryNutz]

So final word is that the DIR-865L is working as designed. Dlink was able to test with there settings and your and they are able to ping DNS. They do get 4 DNS addresses as expected with DNS relay disabled.

What ISP Modem make and model do you have?
Any 3rd party security programs running, i.e. firewalls?
Also what browser are you using to manage the router? Try IE? There is some issues using FF.

[rlcronin]

So final word is that the DIR-865L is working as designed. Dlink was able to test with there settings and your and they are able to ping DNS. They do get 4 DNS addresses as expected with DNS relay disabled.

What ISP Modem make and model do you have?
Any 3rd party security programs running, i.e. firewalls?
Also what browser are you using to manage the router? Try IE? There is some issues using FF.

It may be working as designed, but I am questioning whether the design is correct. If I configure static DNS servers, I want the router to hand out those addresses, and not the ones from my ISP. I've had 4 other Dlink routers (DGL-4100, DGL-4300, DIR-655 and DIR-857) and none of them behave the way the DIR-865L does. They all correctly only hand out the static DNS addresses.

This has nothing to do with my  ISP or modem, but I'll play along for now ... here's the information you requested.

The cable modem is an Arris TM802G.
I have an anti-virus package, nod32 from ESET (just the AV, not the firewall).
I generally used Chrome, but also tried IE9. Makes no difference.
--
bc

[FurryNutz]

Well even though the other routers seemed to behave correctly while you had been using them, you'll have to remember that these new next gen routers, i.e. amplify and cloud routers are probably not designed like before and do have new HW and probably incorporate a different way of handling networking protocols so even though you have specified DNS, maybe having additional ISP DNS is being made available when the DNS Relay is turned off and it's just letting you know, your getting specified DNS along with the auto detected ISP DNS as well. From what they say, DLink says this is as designed and is working as expected for this model router. I was told the DIR-645 behaves similarly in the same way. I'll need to put mine online and check. Normally DNS Relay is on so generally most people don't use specified DNS accept for those more advanced tweeker like to do.  

This maybe a designed in FW tuned for the home user or average user. Again, these are home user router devices.  

[rlcronin]

Alright, now this is just plain weird. I did some more testing. Here's what I found.

I configured the router to not do DNS relay and I did not fill in the static DNS addresses (so that when a DHCP client requested an address, it should be given my ISP's DNS server addresses). Then I forced a DHCP renew on one of my PC's. Indeed, it got two DNS addresses pointing to my ISP's DNS servers as expected. However, I was unable to do any DNS lookups. nslookup told me I had an unknown server and all DNS lookups I had it try kept timing out. Ping could not ping anything by name. My browser could not get to any sites.

So, then I reconfigured the router to do DNS relay (again leaving the stastic DNS server fields blank). Forced a DHCP renew on the PC. Voila, everything worked again (as expected).

But *then* I got the idea to use the Windows network configuration dialogs to change the DNS server options for my nic to NOT get DNS server info dynamically. Rather, I put the very same two DNS server addresses from my ISP in there (the same two addresses that when previously handed out by the router when DNS relay was off, did not work). I then did ipconfig /release and ipconfig /renew. Now ipconfig /all reported the same values it had previously when things were not working, but NOW everything worked fine.

Huh?

To summarize, when DNS relay is off and the router gives my PC DNS server addresses, I cannot get DNS resolution to work (regardless of whether its giving the PC the ISP's servers, or both the static addresses and the ISP's servers (which I still maintain is incorrect, but now clearly not the root cause of the problem)). When DNS relay is on, everything works.

... and by the way, when DNS is failing, it is happening on all the devices on my network, not just my Windows PC's (e.g. my Linux-based work laptop, my wife's iPad and iPhone, my Nexus 7, and my Galaxy S3 all stop being able to resolve addresses). The second I turn DNS relay back on and the devices renew their DHCP address, everything works again.

So come on now, don't tell me this is working as designed!
--
bc

[FurryNutz]

Are you flushing DNS on the PCs after you change router settings?

[rlcronin]

Well even though the other routers seemed to behave correctly while you had been using them, you'll have to remember that these new next gen routers, i.e. amplify and cloud routers are probably not designed like before and do have new HW and probably incorporate a different way of handling networking protocols so even though you have specified DNS, maybe having additional ISP DNS is being made available when the DNS Relay is turned off and it's just letting you know, your getting specified DNS along with the auto detected ISP DNS as well. From what they say, DLink says this is as designed and is working as expected for this model router. I was told the DIR-645 behaves similarly in the same way. I'll need to put mine online and check. Normally DNS Relay is on so generally most people don't use specified DNS accept for those more advanced tweeker like to do.  

This maybe a designed in FW tuned for the home user or average user. Again, these are home user router devices.  

I agree it is possible that it was deliberately designed to hand out both sets of addresses. I'd love to know the rationale for that. Its counter intuitive. If I go to the trouble of specifying static addresses its because THOSE are the servers I want to use. I hate my ISP's crummy DNS servers. I want to use Open DNS and nothing else. I used to be able to do that. Can you verify that if I leave DNS relay on and fill in the primary and secondary DNS server addresses that the router itself is only using those? The status page seems to imply that since it only lists those servers. Or is it actually using all 4 and just not reporting that on the status page? If it *is* just using the static ones, why the difference between that and the no-DNS-relay case where it gives all 4 to the client?

I have also determined that it is not the fact that the router is giving out the 4 addresses that is causing the problem (see above). Something is broken in DNS relay. When it is off, I cannot get DNS resolution to work, period, regardless of what servers are handed out by the router.

Oh, and I suppose I ought to just use DNS relay and forget about the fact that the no-DNS-relay case is broken (and I may well do that if this continues to be an exercise in me beating my head against the wall trying to convince Dlink to fix a problem with a feature that apparently nobody but me cares about), but really, any responsible programmer should WANT to fix this, regardless of whether its just one annoying customer who's complaining. I'm a programmer and that's the attitude I bring to *my* job, Dlink engineers ought to as well ;-)
--
bc

[rlcronin]

Are you flushing DNS on the PCs after you change router settings?

Yep. I do ipconfig /release, ipconfig /flushdns and ipconfig /renew after reconfiguring the router settings.
--
bc

[FurryNutz]

I believe that if DNS relay is OFF, that you have to to input DNS addresses into Windows networking properties to tell Windows what DNS to use since the router is no longer the proxy for DNS.

[rlcronin]

I believe that if DNS relay is OFF, that you have to to input DNS addresses into Windows networking properties to tell Windows what DNS to use since the router is no longer the proxy for DNS.

Except that with every other DLINK router I have used, when DNS relay is off and static DNS addresses are configured, it doles them out with the DHCP response. The 865 seems to be trying to do that (because when you do the IPCONFIG /ALL, the DNS server addresses do appear in the output (whether that be the dynamic ones from the ISP or the static ones and the dynamic ones)), but lookups simply do not work. I have to believe that Windows launches the DNS query and that somehow, when it hits the router, the router is doing something that prevents it from working (since they time out, I'd suspect it is not forwarding them onto the WAN?).
--
bc

[FurryNutz]

I'll put my 645 online tonight and see if I an reproduce this. Might not be the same however they said it was similar.

[rlcronin]

I'll put my 645 online tonight and see if I an reproduce this. Might not be the same however they said it was similar.

Note I modified my previous post. You seem to *always* be there, you answer my posts so quickly! :-)
Maybe I should get them right the first time and rely less on the MODIFY function.
--
bc

[FurryNutz]

 

Possibly. If you have an clear and open pipe to the 865 and it's configured well, it should be as DLink told me they are exhibiting expected behavior.

There another 865 at a store with a return policy up here? Might try another if there is one available.

I'll have DLink check this again and see what they say. I'll have a look with my 857 and 645 tonight and see if I get the same thing or not.

[FurryNutz]

I tested a DIR-645 and a 857 returned the following:
DIR-645 - DNS Relay OFF and specified DNS returned 4 DNS addresses, NSLookup was successful.
DIR-645 - DNS Relay ON and specified DNS returned routers IP address, NSLookup was unknown.

DIR-857 - DNS Relay OFF and specified DNS returned 2 DNS addresses, NSLookup was successful.
DIR-857 - DNS Relay ON and specified DNS returned routers ISP address, NSLookup was successful.

NSLookup ALL was used.

[rlcronin]

I tested a DIR-645 and a 857 returned the following:
DIR-645 - DNS Relay OFF and specified DNS returned 4 DNS addresses, NSLookup was successful.
DIR-645 - DNS Relay ON and specified DNS returned routers IP address, NSLookup was unknown.

DIR-857 - DNS Relay OFF and specified DNS returned 2 DNS addresses, NSLookup was successful.
DIR-857 - DNS Relay ON and specified DNS returned routers ISP address, NSLookup was successful.

NSLookup ALL was used.

Well, I'm stumped.

Do you not have an 865? I have to wonder if you'd see what I am seeing if you tried it with an 865.

Also, for what its worth, I change my log level to "Information" and rebooted the router just to see what the log entries are as its coming up. The very first message I see in the log seems somewhat DNS-related. I'm wondering if you see it too ...

no servers found in /etc/resolv.conf, will retry

If you are, then I guess its nothing. If not, then maybe its a clue.
--
bc

[FurryNutz]

I don't have a 865. Since DLink told me the 645 as similar, I figured I'd test it since I do have that one. 

When you changed the log level what configuration is the DNS set up for when you saw the No Servers Found log entry? DNS relay ON or OFF, DNS automatic or specified in Internet/Manual?

I have been looking for a 865 locally, not in stores here yet that I can find.

Also what NSLookup command are you using? Same as me?