Remote Access an External Hard Drive connected to PACE 5286ac router/modem on uVerse

No, you cannot use the USB connector on any AT&T Gateway for anything more than a low power USB power supply.

You would have to connect your hard drive into a NAS and set up port forwarding to that device through your Gateway, or get a router that can share your USB-connected hard drive and set it up with the AT&T Gateway.

Unfortunately  a Pace Router block port forwarding.   Your suggestion  will not work.

Pace Router has a port forwarding feature which works (in most versions of the firmware).  Did you try to set this up?

Yes    i did try.    Unfortunately ATT has removed the remote access finction.   I can find no way to access the PACE 5862AC Router with a Public IP followed  by a port number so the forwarding function within the firewall settings doesn't work.   Do you know how to activate the Remote Access use a public IP function?

Yes    i did try.    Unfortunately ATT has removed the remote access finction.   I can find no way to access the PACE 5862AC Router with a Public IP followed  by a port number so the forwarding function within the firewall settings doesn't work.   Do you know how to activate the Remote Access use a public IP function?

You wouldn't just happen to be Fixed Wireless, would you?

No  ATT uVerse.   They seem to have removed the Remo Access wireless function.   What menu heading does it appear under?

Okay, I asked because the 5268AC is apparently the only thing they give Fixed Wireless customers, and you had one.  You cannot port forward with Fixed Wireless (it's useless to try, even if the gateway lets you).  I do not have a 5268AC, so I cannot tell you where it is on a 5268AC.  I have a BGW, and on that it is under Firewall > NAT/Gaming.

Remote Admin Access is disabled on all AT&T Gateway firmware.

UPDATE: This article from Support describes setting up Port Forwarding on the 5268AC.  Apparently it's under Settings > Firewall > Applications, Pinholes and DMZ.

Thanks so much.     Until ATT goves me a different modem/router I am stuck like chuck.    I have to use their modem or I don't get my uVerse TV.    

Have you tried doing a factory reset on the Gateway?  Sometimes the NVRAM settings get corrupted between releases.

If the "Applications, Pinholes and DMZ" doesn't appear on your 5268AC, call in to the 800-288-2020 number and tell them you need a gateway that has port forwarding in it.  You should be able to get them to send you a new one.  However, they may send you another 5268AC (which may or may not have the same problem).  Or they may send you a NVG599 or BGW210.