Could ePMP Affect One to One NAT?

I'm hessitant to even ask this, but it's now happened twice.
Running 2.4.1 on Force 100.

As soon as I turn on the one to one, drops all the packets.
I turn it off and packets start again.
It's the router? Nope. I've seen this at two different locations, two different customers. First had a Linksys 1200 (or whatever the 2.4 is called now.) Second location tonight with an Apple TV, Apple cube, Linksys 2500 (or the dual band).
Different APs, different IPs.

It's the static IP.
Nope, running same IPs on several customers, confirmed no replication.

The only common thing is the radio and firmware.

I know it makes absolutely no sense, but it's the only thing I can find.

Thanks much.

What exactly do you mean when you say "turn on the one to one"?



This is Jayesh Parmar from Cambium Networks. I am trying to reproduceĀ NAT issue you seeing and hadĀ few questions for you. Can you please share your contact information where I can reach you or you can call me at +13125934400 or email me at



Well, I'm paraphrasing, but that's basically what we do.
Set the one to one in the main router and enable.
(Or turn it on..)

Perhaps a more detailed answer..
We use site routers, radios are in bridge mode.
Site routers apply private IPs to customer's routers.
At the main router, I assign a static IP to the customers private IP.

(One to one or masquerading might be more familiar term).

Been running over 500+ UBNTs, none of them have had a problem, so it's not just something we started.
We have, oh, roughly 60 or so ePMPsĀ operating the exact same way, most of them with the latest firmware, none of them stop passing packets once the static is assigned, except these last two.

OK, understood - I foundĀ it unclear from the original post /where/ you were performing this NAT, now I understand it's on the gateway router.


is your pool running over? do you have anything to keep a track of that or do you have port overloading setup to catch it?

you may simply have exsuasted your pool and didn't see it ?

I am now 100% conveinced that firmware 2.4.2 is the cause of this problem.

Tonight, I set up a new radio, which had 2.3 on it, running my standard one to one set up..

Upgraded to 2.4.2 and it immedately stopped passing packets.

I may downgrade firmware, just so I can have the NAT, not sure..

I do not understand how the radio could effect this in bridge mode, but it's clearly the cause.

Just FYI..
The latest beta seems to have fixed this issue.

Thank you.

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