"DHCP and NAT" vs. "DHCP Only" & Adding extender router

Can somebody help me with following few questions


I have two routers, in mu house, that are being used in two separate regions with some overlap in signal range. In addition, i am planning to add third router as an extension to one of my router since there is no outlet to hookup wirless in that area.


  • What is the difference between "HCP and NAT" vs "DHCP Only"?
  • What is the purpose of "Bridge Mode" and when it is used?
  • what is recommended depending on below mentioned configuration?


I will have my macbook, ipod, and ipad connected to these devices depending on my location and proximity to the routers in my house.



  1. Airport Extreme Base Station (# 1) router connected to CAT5 for region A
  2. Airport Express Base Station (# 2) router connected to CAT5 for region B
  3. Going to add Airport Express Base Station (#3) to extend Airport Extreme Base Station (#1) range in area A
  4. I am planning to add external drive to Airport Extreme Base Station (#1) for extra storage for pics and movies


Any help will be appreicated if someone can expalin what should be the modes for these routers (#1, #2, & #3) .


Cheers.

MacBook Air, Mac OS X (10.7.4)

Posted on Mar 18, 2013 11:06 AM

Reply
9 replies

Dec 11, 2013 4:08 PM in response to Bob Timmons

It took too long to re find the ISP's router's web gateway, hence it has changed after I turned it into Bridge Mode. Lost internet connection also. anyways I am back again.


Thanks for the help. It's really clear and easily understandable for a home user like me. Not like another tech guy's technical sheet. Thanks


Here is what I did.


ISP's router is in router mode now and DHCP server is "on" there. It is the DHCP/DNS/NAT server now. AirPort Extreme is in bridge mode. As you recommended.


Tho, I still wonder, should I retry ? I mean things like reserving a DHCP for a certain MAC id was lot easier with AirPort Extreme, and I could use only one interface to play with DHCP/NAT/DNS settings. And it feels more secure, probably has higher performance than ISP's router.


I will call ISP guys, and ask if there's an option like changing the router with a modem-only one or allowing me to make AirPort the only router in the network.


Another thing I've noticed today, there was a tickable option in WEB GUI of the ISP's router, "WAN Blocking Enabled". There was an explanation, says that it's to avoid the devices being available to the outer world, something like that. Is this the reason my websites cannot be reached by others ? Should I disable it and allow others to reach the server? It would be a security risk for sure, but is it the only way ?


ISP's router has its own settings that not many people knows and this causes problems to find help. So I can't tell people what's really wrong and what's the exact problem, hence they don't know the router gateway interface. Most people who can help knows about AirPort but it's impossible to know about all the routers and mine can be a really really unpopular one even. This is another reason why I want to set AirPort as the main router, then it would be easy to get help also.

Mar 18, 2013 12:25 PM in response to Shmalick

DHCP and NAT is an ordinary router providing a firewall and DHCP services (automatic IP addresses). DHCP only doesn't provide a firewall but it does provide its own DHCP. Bridge mode just makes the device an access point with no routing capabilities.

I am assuming (1) is directly connected to the Internet via a modem.

  1. DHCP and NAT
  2. Bridge mode
  3. Extend a wireless network

(1) and (2) should have exactly the same network name, password & security type.

Mar 18, 2013 2:16 PM in response to Shmalick

#1 and #2 cannnot both be connected to a true "modem".....(a true modem has only one Ethernet port).....but #1 and #2 could be connected to a modem/router or gateway type of device.


It sounds like your "modem" is really a modem/router or gateway type of device, and if that is the case, then both #1 and #2 would be configured in Bridge Mode....since the modem/router would already be providing DHCP and NAT service for the network.


You never want two or more devices all trying to act as routers providing DHCP and NAT on a network since this results in mutliple devices trying to issue IP addresses and offering multiple firewall functions.


You only want one device on a network providing DHCP and NAT. Other routers must be configured in Bridge Mode to operate correctly on the network.


So, before you try to proceed further, it is important to clarify whether you really have a "modem" or another type of device that is acting as a router as well as a modem.


What is the make and model number of your "modem"?

Mar 18, 2013 2:20 PM in response to Bob Timmons

The mentioned configuration is in the house in Beijing and am aheading there end of this month from USA. I will be able to provide more information about the equipment. Just preparing for it right now with purchase of Apple Base stations. Currently Item #1 & #2 exist with separate network names and passwords and seems that it needs to corrected based on responses.


Cheers,


S

Mar 18, 2013 2:28 PM in response to Shmalick

You can keep separate names and passwords on #1 and #2 if you want, but you will need to log on to each AirPort separately when you move from one area to another.


Configuring all AirPorts to use the same wireless network name, same wireless security and same password will, in effect, create one "big" network.


Computers will be able to "roam" from one area to another and stay on the same network since the computer will automaically switch to pick up the best signal from the closest AirPort device.

Dec 10, 2013 9:09 AM in response to Bob Timmons

I have an AirPort Extreme, and it's plugged into my ISP's router. What I want is to use the AirPort Extreme in DHCP and NAT mode. So I turned DHCP Mode off on the ISP's router. But now, I have double NAT error, I have internet access after I said ignore this error, but I want it to be fixed.


Let's say 192.168.0.1 is the ISP's modem/router's IP. Then 192.168.0.2 will be the AirPort Extreme. And when I want other devices to use the AirPort Extreme as router, I will have their router address 192.168.0.2, am I wrong ?

OR should it be 192.168.1.1 ? Could you please explain that ?


What I want is to host my websites on my Mac Mini with OS X Server. I know this is not required, not even an AirPort, but I want to use the Server app as the only controller to work with my network, rather than going to ISP's router's interface anytime needed. It will be easier to control, and will keep things all in one place.


Thanks in advance

Dec 10, 2013 9:42 AM in response to pbcaer

So I turned DHCP Mode off on the ISP's router.


That will not turn off NAT on the ISP router, so you will still be fighting a Double NAT error on the network.


If you want to run the AirPort Extreme as the main router providing DHCP and NAT for the network, then the ISP modem/router must be configured to operate as a simple bridge mode modem.


Whether or not that is even possible would be a question for the support folks at the ISP.


Even if it might be possible, the next question would be whether the ISP will support that type of setup.


I understand that you want the AirPort Extreme to act as the router for your network, but life will be a lot simpler if you allow the ISP modem/router to provide DHCP and NAT services for the network and then set up the AirPort Extreme to operate in Bridge Mode.


Another simpler option might be to replace the ISP modem/router with a simple bridge mode modem.....if your ISP offers that type of product.

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"DHCP and NAT" vs. "DHCP Only" & Adding extender router

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