Nighthawk x4s d7800, dsl port question

[Mallowsm]

Can I please ask what connection is on the back of this router for the DSL side, I have tried both RJ11 and standard ethernet, neither fit. Does anyone know what connection this is, from the grey port to the box that's coming into the property from my home

[plemans]

It should be RJ11

[antinode]

> [...] what connection is on the back of this router for the DSL side,
> [...]

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual.  Read.  Look for "Technical
Specifications" and "DSL".

> [...] I have tried both RJ11 and standard ethernet, neither fit. [...]

   The User Manual says "One RJ-11 asynchronous DSL (ADSL/VDSL) port".
That's what I'd expect.  I can't see what you're doing.

> [...] the box that's coming into the property from my home

   I can't see any of that, either.