Airport Extreme and Westell DSL modem

My question is whether to set this up as a router or a base station

Not sure what you mean by this as Apple calls a router a base station. If the Westell device is providing routing functions, then the AirPort Extreme should be set up in Bridge Mode to work correctly on the network.

If you have two devices, both handling DHCP on the network, there's bound to a conflict sooner or later.

Right now I have the Airport setup as a router with NAT unchecked

Are you tallking about the settings to "enable default host at" and "enable NAT port mapping"?

Unchecking these boxes does not turn off NAT if you have the AirPort Extreme configured as a router......with the setting for Connection Sharing set to "Share a public IP address".

Ref: AirPort Utility > Manual Setup > Internet icon > Connection Sharing

You turn off NAT (and DHCP) by configuring the Connection Sharing setting to "Off (Bridge Mode)".

John, I have the exact equipment configuration you've referenced and the AirPort Extreme works reliably in BRIDGE mode — allowing the Westell (7500?) to provide PPoE/NAT/DHCP/DNS. Use the AirPort's WiFi security (WEP & Cloaking) — but you'll find all your other referenced routing & security functions within the Westell. (The Westell is only 802.11g-capable, so turn-off its radio.) This configuration also permits quick re-configuration, if you need to isolate the AirPort for troubleshooting LAN vs.WAN issues. That's gonna be way-useful when contacting your sister's ISP support for possibe troubleshooting assistance...

If your recently purchased AirPort Extreme (5G?) continues to require frequent resetting even with a new configuration (you didn't say why it's needed...) then I suggest you explore your swap-out options with Apple Support, or the the Apple store where it was purchased.

Hope this helps!

Thought I'd take a 2nd swipe at this, to address some of John's other concerns (lke NAT'ing) along with questions others may have about the AirPort Utility user interface...

Coming from the WIN~PC world you may have noticed that Apple frequently prefers to employ pop-up configuration options, rather than the radio-buttons that are common on WIN PC-centric user interfaces (like Netgear routers). While pop-ups permit a less-cluttered interface, they also tend to obscure what choices are available, and can make setting up new equipment less-intuitive. Making Apple's use of pop-up menus even more-entertaining, you'll discover that some choices are context-sensitive, based on your previous selections. Beyond that, if you hold-down the Option key while clicking on pop-up/pull-down menus, you may also see an expanded range of choices. (Apple's interface guidelines were mostly established 25+ years ago, when users' interactions with their gear were far simpler; the AirPort Utility is a good example of what can go wrong when you become a slave to fashion.) Go-ahead and explore, though — without worrying about messing-up a working config, because your selections won't go live 'til you save 'em ('cept the status light) & you can always quit the AirPort Utility without saving changes. When you finally settle upon a working configuration you like, please export a copy of those settings via the File Menu so you can quickly restore them or switch between different personalities if needed. (What a breakthrough, if people could do that, eh?)

Enjoy!

John — you still haven't confirmed if we're talking about a Westell 7500 supplied by Verizon; their firmware leaves the router unlocked for local admin (Grrr!) after the 1st log-on (defaults = "admin" & "password"). Entering 192.168.1.1 into a browser should get you to the router's home page. If you encounter any additional/different login challenges, you'll need to check with whoever initially configured the router or reset it back to default settings. While you're in there, I suggest reserving a few IP addresses from the DHCP range, & use 'em for any network attached printers AND the AirPort Extreme (needed for time sync & if you'll be hosting anything via its USB port). I've never seen a manual for the 7500, since they're only supplied as OEM, afaik, & their firmware is carrier-specific. Verizon DSL has a 24-7 Mac-specific support queue, and they're often good at it. Since there are many thousands of these Westell 7500s deployed, you'll find lots of useful info via Google as well...

Good luck! (And, remember there's a "Like" button right under here ... )

If you want to use the Versizon / Westell device "as is", then you must configure the AirPort Extreme as a "bridge"

AirPort Utility > Manual Setup > Internet icon > Connection Sharing = "Off (Bridge Mode)"

If you want to use the AirPort Extreme as the main router, then you must configure the Verizon / Westell device as a "bridge". Verizon's instructions for this are here:

http://www22.verizon.com/residentialhelp/highspeed/networking/setup/questionsthr ee/123756.htm

Sorry, I have not used a Westell product for some time, so don't have any specifics on their products.

Maybe a Westell support forum could help?

John,

The 6100 is an older product (~2006?). Depending on how long your unit has been in service, there may have been firmware updates released by Verizon which will greatly affect the appearance and contents of pages presented by its embedded server. I advise you to update the 6100 firmware if needed, before changing the configuration. Verizon will often ship out a current DSL router to Mac subscribers on request, since Westell routers can't be flashed from a Mac. (You'd probably get a 7500). If you do choose to continue configuring the 6100, look for an "Advanced" tab where you can turn-off IP address distribution for a private LAN. That should effectively put the 6100 into bridge mode. However, Verizon employs dynamically-assigned DNS servers; without locally-stored DNS entries, I'm uncertain about how well the 6100 will continue to negotiate DNS lookups in bridge mode.

I can't offer any more-specific advice about configuring the 6100 since I've never used the product. However, based on what I do know about Verizon's suport for their hardware, I still believe that you'll be creating extra challenges down the road by chosing to configure any DSL router as a bridge, since Verizon won't provide troubleshooting support for that configuration.

Now that this discussion has substantially drifted away from anything relating to an Apple AirPort, I believe you'll get better configuring advice from Verizon DSL tech support (800 567-6789) and/or Verizon's DSL "High-Speed Internet" Help pages. So that other forum visitors may benefit from reading this discussion, please come back and post a descrption of the solution that worked for you.

Thanks and good luck!