FTP Server Problem with Gatway acting as a modem with a linksys router
I am using the AT&T U-Verse Home RG as a modem. I have a Linksys WRT54G router that I am using for my computer equipment. The Linksys is plugged into one of the LAN ports on the back of the RG and to the WAN port on the back of the Linksys. The Linksys is set to DHCP and the RG is set to DMZ mode for the Linksys router. This allows the Linksys router to get the WAN IP Address and to connect to the internet. The DMZ mode is suppose the unblock all ports to the selected IP which is pointing to my Linksys router. The Linksys router connects to the internet without any probelms, this part all works fine.
My problem is with my NAS Drive's FTP Server. The NAS is pluged into the LAN port on the back of the Linksys router. I configured port fowarding on the Linksys to allow port 21, and that points to my NAS Drive's Internal IP Address. I am able to connect to the FTP Server locally within my network, but I can't connect remotley (at my other house over the internet ). I use my DNS name (ftp://example.com) NOT my internal IP address (ftp://192.168.2.1) to connect to the FTP Server locally. I can't connect to it remotley. I am not restricting NAT on my Linksys router. I am using all of the correct IP addresses. But I still can't figure it out. This all worked fine before I got U-Verse when I just had a DSL modem with the Linksys router.
Can there be some kind of conflict between the RG and the Linksys router? Is there a double NAT issue? I am tollay out of ideas. The only thing I didn't try to do was restart the Linksys router after I configured my NAS, should I?