OK, I got it to work, but it's weird. Let me explain:
1. I logged out of ACT on my MacBookPro
2. I connected the Ethernet to the Airport Extreme
3. In Airport Utility, I chose DHCP instead of PPPoE
4. Airport Extreme went solid Green from blinking Orange
5. I ran Safari on my
Mac and went to one of my bookmarks
6. It automatically opened the ACT Portal page and asked for my login
7. I logged in on my MacBookPro
8. I am able to browse and get mail and do anything on my MacBookPro.
Now comes the kicker:
9. I turned on my iMac, which is also connected to the same Airport Extreme wifi.
10. The iMac is also able to browse and get mail and do everything, but I never had to login there. The login I did on my MacBookPro held OK for this too.
11. I signed on to the Wifi on my
iPad, and I am able to browse on that too.
12. My iPhone5 and my wife's iPhone5 are aso on and working now.
So, now I have all my devices working on the Airport Extreme with ACT Fibernet.
The only thing is, it is not PPPoE, but DHCP.
Yet to do:
I have to see now if this one login I did ow holds on forever or if it asks me to login every 24 hours like it did when I was hardwiring the ethernet to my MacBookPro. I somehow suspect it will ask me to do so, because it is not my
router that's logged in, but one of my client machines.
I suspect I cannot configure PPPoE for ACT simply because there is no modem. ACT have a switch or hub or something on the next building with about 16 Ethernet ports, and from that next house they have run an Ethernet cable right into my house, so there's no mode, per se to connect, and therefor I suspect, no PPPoE for me to configure. Of course, all this is from a layman's perspective with no knowledge of networking, so experts here might have a different opinion or at least a more educated one.
I would like to thank the two of you, gopichandpai and uberjon, for your prompt assistance. I am much obliged.
Cheers