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The Graveyard - Products No Longer Supported => Routers => DIR-850L => Topic started by: alcatos on March 30, 2015, 05:54:01 PM

Title: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on March 30, 2015, 05:54:01 PM
I'm having the strangest issue with my DIR-855LA1, Firmware: 1.09 Tue 27 Aug 2013.   I am simply not receiving any requests from my network to my external DNS servers.   I have specified a Dynamic IP internet connection type (DHCP) under "Manual Internet Connection" on the Internet setup page, with a custom Primary and Secondary DNS server, both of which I own and both of which are located outside of the my network.  I can see in the dnsmasq logs on my servers that I do not receive requests; despite having the relevant UDP / TCP ports open for DNS queries, etc.

My DIR-850LA is bridged to a WAN gateway modem that is provided by my ISP, if that is relevant.

After much experimentation, it seems that the only way to get my DIR-850LA to query my external DNS servers is to specify the connection type as Static, along with the IP address issued by my bridged WAN connection, the gateway IP address and my two DNS servers.  The MTU is set at 1494.  I'd set it to 1474 at one point, but that completely killed the internet connection.  I've also muddled around with the "Enable DNS Relay" feature as well, and am not 100% convinced that it does much of anything :p  However, this solution is unreliable as all DNS resolution fails after a day or so.

Am I doing something wrong here?  Can I not specify custom DNS Servers with a Dynamic IP connection type?

If I am missing any relevant information, please let me know!

Thanks in advance.
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on March 31, 2015, 08:34:08 AM
Link>Welcome! (http://forums.dlink.com/index.php?topic=48135.0)



Internet Service Provider and Modem Configurations
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on March 31, 2015, 01:32:43 PM

Link>Welcome! (http://forums.dlink.com/index.php?topic=48135.0)


[/list]


Internet Service Provider and Modem Configurations
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on March 31, 2015, 01:45:29 PM
How do you mean that the 850L is bridged to your ISP modem?
How is it physically connected to the modem? WAN or LAN port used to connect to the ISP modem?
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: Hard Harry on March 31, 2015, 01:54:26 PM
Any difference if you enter in the IP of the alternate DNS rather than domain?
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on March 31, 2015, 06:30:26 PM
Hi guys,

How do you mean that the 850L is bridged to your ISP modem?
How is it physically connected to the modem? WAN or LAN port used to connect to the ISP modem?
The router is bridged to the modem via Internet port, not  any of LAN ports.

Any difference if you enter in the IP of the alternate DNS rather than domain?
I've specified them as IP addresses not domains.


Thanks again,
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: Hard Harry on March 31, 2015, 06:55:05 PM
I think there may be some confusion over the different ways you can use the word bridged. Typically it's any item or connection that works on the 2nd layer of the OSI model. This is used in context by the saying "the modem is bridged or bridge mode" meaning it doesn't handle IP/TCP/Ports or anything a router would do. Basically turns a gateway into a modem. If your router IS bridged to the modem then it's acting as an Access Point, and might describe why DNS isn't working.

If you mean the gateway is in bridge mode, what model gateway do you have?
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on April 06, 2015, 07:07:02 AM
Any status on this?

I'm having the strangest issue with my DIR-855LA1, Firmware: 1.09 Tue 27 Aug 2013.   I am simply not receiving any requests from my network to my external DNS servers.   I have specified a Dynamic IP internet connection type (DHCP) under "Manual Internet Connection" on the Internet setup page, with a custom Primary and Secondary DNS server, both of which I own and both of which are located outside of the my network.  I can see in the dnsmasq logs on my servers that I do not receive requests; despite having the relevant UDP / TCP ports open for DNS queries, etc.

My DIR-850LA is bridged to a WAN gateway modem that is provided by my ISP, if that is relevant.

After much experimentation, it seems that the only way to get my DIR-850LA to query my external DNS servers is to specify the connection type as Static, along with the IP address issued by my bridged WAN connection, the gateway IP address and my two DNS servers.  The MTU is set at 1494.  I'd set it to 1474 at one point, but that completely killed the internet connection.  I've also muddled around with the "Enable DNS Relay" feature as well, and am not 100% convinced that it does much of anything :p  However, this solution is unreliable as all DNS resolution fails after a day or so.

Am I doing something wrong here?  Can I not specify custom DNS Servers with a Dynamic IP connection type?

If I am missing any relevant information, please let me know!

Thanks in advance.
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on April 07, 2015, 07:00:01 PM
I think there may be some confusion over the different ways you can use the word bridged. Typically it's any item or connection that works on the 2nd layer of the OSI model. This is used in context by the saying "the modem is bridged or bridge mode" meaning it doesn't handle IP/TCP/Ports or anything a router would do. Basically turns a gateway into a modem. If your router IS bridged to the modem then it's acting as an Access Point, and might describe why DNS isn't working.

If you mean the gateway is in bridge mode, what model gateway do you have?

Sorry should have clarified, the router WAN port is physically bridged (Layer 1) to the modem.

I'm starting to think that the "DNS Relay" option may have something to do with this.  From what I've read on DSLReports, the DLink router definition of DNS Relay does not mean that the router will cache DNS replies, but instead it means that the router will proxy DNS queries to the custom primary and secondary DNS servers, if the client devices has the router's IP as their gateway.  I'm going to do some tinkering around with that setting again.

Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on April 08, 2015, 12:28:03 PM
Some if not most of D-Links home class routers may not support DNS queries. Others have set up Raspberry Pi Servers to help with this...
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on April 08, 2015, 04:36:14 PM
Yeah, I have a few Raspi's kicking around, but I doubt the wifi dongle's TX power would be strong enough, or the 900MHz core could handle the load.

Anyhow, it seems to be working now.  Fingers crossed and knock-on-wood and all that.  ;D
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on April 08, 2015, 06:09:47 PM
Let us know what you have done so far please...
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: alcatos on April 08, 2015, 08:57:00 PM
Let us know what you have done so far please...

Just enabled "DNS Relay" and defined custom dns servers
Title: Re: DIR-850L won't query custom DNS servers when Dynamic IP (DHCP) is specified
Post by: FurryNutz on April 08, 2015, 09:52:26 PM
Kewl, hope this works for you...