Hi i don't know how to work out ddns with load balance (never tried myself, so come back to your post for this, if any reply)...
but i am posting only to the point of firmware modem codes
The modem codes 2471201(my opinion is to try this one first),244001,2431301,259201 should synchronise at its highest
ftp://ftp.draytek.com/Vigor2830/Firmware/v3.6.4%20Single%20band/Annex%20A/

Thanks for the link.

My modem firmware seems to be 232201 - will I notice much difference with the other one?

What about my Vigor 120 on WAN2?

I don't seem to be able to see anywhere what connection speed etc I am getting on WAN2 like I can on WAN1.. Any idea?

Cheers!

With the 3 modem codes i mentioned, speed should go up by 0.5 - 1 mb (at the distance you are from exchange depending each boot and time of the day rebooted)

The vigor 120 has few modem codes as well which can give little better speed but don't remember them right now because has not use it for long time

To work the 120 at wan 2 you need to set WAN >> General Setup >> wan 2 (enable & always on) ... then
WAN >> Internet Access >> drop menu or page details >> set it at PPPoE then add your isp account password and username

I'll give them a whirl at some point then.

I already have both WAN connections working like a charm - load balancing is working and I can push certain ports through particular WAN connections.

Only thing I can't figure is DDNS - sometimes I can connect to my LAN externally and other times I can't... (but I have a separate thread for that!)

Voodle wrote:
Personally I used a mini AP such as the TP link wr702n to connect to my iPhone 4's personal hotspot and use that connected to the WAN2 port for some double NATted but functional backup internet

Hi Voodle! You seem to have solved a problem I'm grappling with, and I'd be very grateful for your help if you have the time.

I've got a vigor 2820n (firmware version 3.3.8_232201). The WAN2 port gets internet from an ethernet feed from my Wireless ISP (County Broadband). When that feed is down, I want to be able to provide backup internet access using my mobile phone's 3G hotspot. But I can't figure out how to configure the WAN2 port. Perhaps you might share your settings?
(a) Should I configure the TP link WR702n in 'Client mode' giving it the password of the hotspot etc)? Or some other mode?
(b) Do I need to change the TP link's internal IP address to what my home lan uses (192.168.1.0)?
(b) Should I then plug it's RJ45 port into WAN2 on my 2820?
(c) But then what should be the settings in the 2820's 'WAN >> Internet Access' config pages? Currently, for accessing my WISP, only the PPPoE tab is enabled. The other two tabs ('Static or Dynamic IP' and ''PPTP/L2TP ' are both disabled).