# No DNS Server/ Double NAT



## thewaxtadpole (Aug 15, 2010)

I have an optimum online cable router -> 1TB Time Capsule with an ethernet connected PC and then multiple connected mac/apple devices. 

I randomly get yellow lighted with two errors:

NO DNS SERVERS
DOUBLE NAT

I have read that this MAY have had something to do with recent firmware updates, however I have only had this installed with most recent firmware.


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## Satcomer (Aug 16, 2010)

If the Time Capsule is behind the cable router then the cable modem/router that is acting as the main NAT server the closet to the modem should be the only NAT server in a local network.  So open the /Applications/Utilities/Airport Utility and in the time Capsule setting click on the "Manual Setup" button. When the Manual Setup comes up click on the 'Internet' tab and in there move the 'Connection Sharing' toggle to "Off (Bridged Mode) and save that setting. 

For the DNS setting log into your cable modem router and then open another tab go to OpenDNS.com and open a free account (if you live in North America or the European Continent) (here is an instructional video for your router setup) and control your own DNS.  You can set it up in your main router for your whole network.

Good Luck.


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## thewaxtadpole (Aug 16, 2010)

I tried updating both.. However only found luck with OpenDNS.  Once I put the router into bridge mode I don't get a connection.

I am still standing by because the problem does not happen 24/7


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## thewaxtadpole (Aug 16, 2010)

Exactly what does OpenDNS do?


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## Satcomer (Aug 17, 2010)

thewaxtadpole said:


> Exactly what does OpenDNS do?



It lets you control your own DNS to block bad sites that host trojan as well as others. If you watch the video I had in my last post it will explain it all.


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## Whitehill (Aug 19, 2010)

My DSL started with Verizon, now Fairpoint.  At first the performance was way below what I was paying for, 3mb down 750kb up.  Their tech support was useless and basically told me _tough luck_.  I switched from their servers to OpenDNS's and the service immediately jumped up to the proper speeds.  Switch now, even if you don't use their other freebies.


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## Satcomer (Aug 29, 2010)

thewaxtadpole said:


> I tried updating both.. However only found luck with OpenDNS.  Once I put the router into bridge mode I don't get a connection.
> 
> I am still standing by because the problem does not happen 24/7



No the Main router (the one that is closet to the modem) should be the one that does NAT.  This is ONLY for a ROUTER. If the ISP modem/router is not a router then it will just dish out 1 IP. That's all an ISP sells a customer. That is why people use routers at home because more and more devices needs IPs. 

1. Can you log into the ISP router?

2. A PC is NOT a switch so you network design is flawed!

3. Design the network as follows:
     a) ISP modem
     b) ISP Router (that some ISPs are including in the modem they give customers). If this is so, log into that ISP router and make surer it is acting like a router, move to set four.

4. Wireless Airport in Bridged mode. 

This way you can plug the PC into the either that ISP modem/router and the Mac on wireless will be in the same subnet to share files and the dreaded  NAT will go away Because only the ISP router is dishing out IPs.


This all depend that the ISP mode/router does do NAT.  Please post web links to the modem so I can tell if it does NAT (Network Address Translation).


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