N66u passes IPv6 in bridge mode, but won't in router mode

[Ravlen]

Just got gigabit fiber installed in my new house (in Japan). I got an N66U to power it, but completely forgot that you have to use the provider's supplied router to make use of their VOIP service. I decided to just roll with it and plug the N66U into the supplied Aterm BL900HW, which is a 4-port N class gigabit router. Now, I know double routing isn't exactly ideal, but I wanted to play with the N66U, and the Aterm is all in Japanese so any tinkering with that is risky (mainly because a call to the support line will have to be done in Japanese, not my native language).

With a PC plugged directly into the Aterm, the PC gets IPv6 fine. With the N66U plugged into the Aterm in bridge mode, and a PC plugged into the N66U, the PC gets IPv6 fine, although the N66U doesn't seem to get an IPv6 address (and I can't see any settings for IPv6 with the N66U in bridge mode either, not even an entry for the device's own IPv6 address).

When I put the N66U in router mode, it doesn't pick up any IPv6 settings, and doesn't pass IPv6 traffic, although IPv4 is fine. I've tried a half dozen firmwares, both new and old Merlin firmwares (based on other recommendations I found while googling the problem), new and old Asus firmwares, and as a last resort DD-WRT. It just won't pick up IPv6, or pass IPv6 traffic when set as a router.

I'm assuming it's a configuration issue since it doesn't even work with DD-WRT. Are there extra configuration issues related to plugging a router into another router? Shouldn't it at least pick up an IPv6 address, or self-configure a stateless address?

This is not critical, but it's something for me (a pre-IPv6 networking guy, out of the biz for a decade) to tinker with, and it annoys me to no end that I have no idea what's up. I'm going to read up more on IPv6 and see if I can figure out what the IPv6 address SHOULD be in the N66U, and hard code it as a static address to see if that works... but in the meantime, any ideas what's wrong?

Ravlen

 

[microchip]

This may sound strange but at least for me when I modify any setting on the IPv6 page, the IPv6 stops working, meaning that when I click Apply button, all the fields become blank (the address/LAN/etc fields on the page) and the router no longer handles IPv6 or gives out IPv6 addresses. The only way to "fix" this is to either reboot the router (not in favor of this) or unplug its WAN cable and wait for 5 seconds or so then plug it back in again, and after some seconds the router picks up an IPv6 address and the IPv6 page correctly shows all the IPv6 stuff.

 

[Nullity]

Is this happening because a bridge functions below the IP layer? Bridges can send an ethernet frame encapsulating any higher network layer, like IP, TCP, HTTP, DNS, while only needing to understand ethernet frames.

A router operates on the IP layer, so it must understand that layer to network properly.


I think...