From the Ooma Telo Setup page I narrowed the range of DHCP addresses to a single address and then from the Airport Utility Network page just set the Router Mode to DHCP and NAT, then updated the settings. Next, on the home screen I selected the Double NAT error message and told the Airport Extreme to ignore the error. Some have also suggested to go to the Advanced Settings page and set the Port Forwarding to the same DHCP address as set on the Home Network page within the Ooma Telo Setup, but I did not do that step.
My objectives in this set-up: 1) use a configuration recommended by Ooma for maximum call quality, 2) keep the Airport Extreme in DHCP mode for all the LAN wired and wireless devices, 3) eliminate prospect of conflicting NAT traffic from the Airport Extreme and the Ooma box. I'm not a network guru so am not sure if I've accomplished step 3 in this approach.
Thoughts? Everything seems to be working...but is it secure, and might I suffer speed degradation by having two devices in DHCP mode, even though one of them (the Ooma) can only use one address (172.27.35.2)?
Thanks in advance.
The double NAT issue, is not an issue, just that the flashing amber light that will bother some people.
I know there is a procedure to turn off the double NAT amber flashing light in the Airport Extreme.
I'm short of time right now, so if you don't find it, let me know and I'll look later.
Below are some Airport Extreme Configuration threads the may be helpful:
viewtopic.php?f=9&t=12981&p=97319&hilit ... Nat#p97319
viewtopic.php?f=2&t=12731 Works with Apple Airport Extreme
viewtopic.php?f=9&t=12382&p=88998&hilit ... eme#p88998 Port forwarding for Camera Setup
viewtopic.php?f=2&t=12094&p=88279&hilit ... eme#p88279 Bridge mode/DHCP mode
viewtopic.php?f=2&t=11474&p=81709&hilit ... ght#p81709 Double NAT Flashing Yellow light