2021-02-15

OpenWRT: WRT54GL: Backfire: IPv6 issues

While having a Debian boxen as a router feels nice, I kept on longing for something smaller and quieter. I then remembered that I still had my old WRT54GL somewhere. After upgrading the OpenWRT firmware to the latest supported version for that hardware (Backfire 10.03.1, r29592), I installed radvd and wide-dhcpv6-client. Configuring radvd to deliver consistent results was easy enough.

The issue I keep on experiencing is the external interface (wan) dropping the IPv6 address it received from the ISP via router advertisement, which in turn kills the default IPv6 route to the outside world. Logging in via SSH and manually running "rdisc6 eth0.1" restores the IPv6 gateway. I just honestly wished I didn't have to do this every time I need to reboot the router.

Does this issue sound familiar to anyone? What was the solution?

PS: No, I won't just go and ditch this WRT54GL just because new toys exist on the market. This is obviously a software issue, so I need a software solution.

PPS: IPv6 pretty much works out of the box on the Debian boxen I had been using as my router. I previously wrote about this on my blog. Basically, it's unlikely to be an ISP issue.

1 comment:

Avian said...

I've encountered a similar problem when my ISP was not sending Router Advertisements correctly. The advertisement timed out since the ISP wasn't refreshing it properly. In my case I only lost the route, not the IP and prefix delegation, so it doesn't sound like the exact same problem you're having. I just want to say that perhaps the problem is not at your end. I've written about my problem here.