Sunday, August 14, 2011

Motorola Surfboard SB6580 Playing Nice With Apple's Airport Extreme


This past week my Zoom cable modem was dropping my connection a lot due to the increased speeds that Cox was delivering in my Premium Internet package. The current service should deliver around 25Mpbs down and about 15Mbps up but I was not seeing anywhere near that.  I had the Cox technician come out to adjust some of the connections inside and outside the house and he recommended using a Docsis 3.0 compliant cable modem.  I did some research and found the Motorola Surfboard SBG-6580 which has a DOCSis 3.0 cabel modem coupled with a dual Wireless N router that can have both a internal and guest wireless broadcast.

Inside the house I have the first generation N Wirelless Apple Airport Extreme which has been functioning as my router for the past 3 or so years.  First I read a couple of posts on just disabling NAT on the Surfboard and keeping my router configuration on the Aiport the same.  This worked alright but was prone to losing connectivity since there is really no way to completely disable the router portion of the Surfboard. This resulted in both devices being disconnected and then the Surfboard being put back online followed by the Airport.  

To avoid this issue, I opted to do the following:

  1. Use the Motorola router's NAT (aquiring the public IP from the ISP)
  2. Setup the Airport to hand out a series of addresses on the same submet (10.0.x.10 - 25)

Below are the setup screens for the settings in both the Surfboard and Airport:


Once the Surfboard's modem connects, it will establish that verified handshake with your ISP, then the router gets the public address and distributes an address to the Airport.  The airport is given a specific range of address which get marked STATIC on the Surfboard and all your devices are now talking to the Airport without any disruption.  This has been bomber even if the power goes out and the system comes back up.  Below are my connection stats: