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ATT Double NAT

Larry - W9FLA
Larry - W9FLA Member ✭✭
edited September 2019 in Remote Operation (SmartLink)

Last year I obtained a copy of V2 SSDR and a new win10 I7 laptop to be able to operate my Flex remotely using SmartLink.  I was unable to connect the two as was Flex support using TeamViewer.  The conclusion was that my ISP, ATT, uses a double NAT to supply my Internet.


I was offered help by an independent individual who indicated he had been able to successfully use the same or similar device with SmartLink.  I followed his instructions but the modem bricked just outside of warranty requiring a new purchase.


Has anyone found a workaround for the ATT double NAT problem?  If not, are only a few Flex uses affected allowing this limitation to be ignored?


  • W5AP
    W5AP Member
    edited September 2019
    I think that is what I had, but please explain what double NAT is.

    I contacted my ISP and explained that I needed to access my equipment from out on the WAN. He said I needed to set up a static IP - which I did, and pay for.   That solved the problem.  I've also heard that others are using a virtual private network - but I didn't go that route.
  • Larry - W9FLA
    Larry - W9FLA Member ✭✭
    edited September 2019
    Here is what I found and believe. 

    Double NAT
    , or multiple routers on one network, is when two or more Routers' Network Address Translations (NAT) are placed one after the other.

    Double NAT (Double Routing) is most common when you connect an additional router to the existing router or gateway your Internet Service Provider gave you.

    In my case, ATT provides me with a public address, the first NAT.  I believe that my router then translates this to my internal LAN's NAT of 192.168...
  • As I understand Double NAT will prevent remote operation of the Flex - I have to change to a different product which not fixed IP is externally addressable.

  • KR5OG Paul K
    KR5OG Paul K Member ✭✭
    edited December 2020

    Mike -VA3MW has mentioned the second router in one of his VLOG’s and I believe he indicated difficulty unless the second router has to be setup in Bridge mode, and some routers are not capable of bridge mode.



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