BT hub 6 connection to neatgear ac1200

> [...] BT are moving phone lines to digital meaning I have to plug in
> the phones into the bt hub. [...]

   And that does what, exactly, to your Internet service?  Knowing
nothing, I'd guess that your old DSL service will go away, being
replaced by whatever feeds your (still unspecified) "the bt hub",
eliminating the need for your D6220 DSL modem+router. (But what do I
know?)

> [...] What I'm looking for is for the dsl line to plug into the bt hub
> [...]

   Which makes no sense to me.

> [...] I've tried to plug a cable from the bt hub into the red wan port
> and the standard ports but the Internet is not passing through. [...]

   Did you also reconfigure the D6220 to stop it from trying to use its
DSL port and all the Internet-connection settings which went along with
that DSL connection?

> [...] Do I need to change anything on the netgear router to accept the
> Internet connection from the bt hub?

   I'd expect so.  And, after you do all that, you'd have something
almost as good as a direct connection directly between the (still
unspecified) "the bt hub" and your (unspecified) alarm.

> [...] so the alarm with continue to pick up the netgear WiFi. [...]

   Your (unspecified) "the alarm" uses a _wireless_ Internet connection?

   The purpose of the D6220 was to provide you (and your (unspecified)
"the alarm") with an Internet connection.  If the (still unspecified)
"the bt hub" will now be doing that job, then you don't need the D6220
to do that job.

   If your (unspecified) "the alarm" uses an Ethernet (wired) connection
to the D6220, then it should be able to use an Ethernet connection to
the (still unspecified) "the bt hub".  If your (unspecified) "the alarm"
uses a wireless connection to the D6220, then it should be able to use a
wireless connection to the (still unspecified) "the bt hub".  To make
that change easier, you'd want to configure the (still unspecified) "the
bt hub" to use the same wireless SSID and passphrase as the D6220 used.

   There's nothing magical about your D6220 which makes it essential to
the operation of your (unspecified) "the alarm".  But, if you're wedded
to continuing to use the D6220 with some other router (which, I assume,
is what the (still unspecified) "the bt hub" is), then you probably
should configure the D6220 as a wireless access point, rather than as a
full-function router.

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual (at least).  Read.  Look for
"Use the Modem Router as a WiFi Access Point Only".