I've got a Cisco RV215W Wifi router on a Comcast residential connection where after a day or two, the WAN IPv6 gateway address drops out, and i can't make IPv6 connections. If I look at the System Summary page, it will show the gateway address under IPv6 Configuration as blank. So far, I'm having to reset the router to get the IPv6 WAN Gateway back (typically, I go to Networking/WAN/IPv6/IPv6 WAN Configuration, and click the Save button. This will typically reset the router enough that when it comes back, there is a non-blank WAN IPv6 Gateway address).
When I do have a WAN IPv6 Gateway address, it's an FE80 address, so evidently the Comcast router is handling me a link-local address for the WAN IPv6 Gateway. I'm also seeing a lot of these in the RV215Losing IPv6 gatewayW logs:
ICMPv6 RA: ndisc_router_discovery() failed to add default route
I suspect the two are connected. I've been able to find examples in Debian or Ubuntu where these messages occur often when the network configuration has a hard-coded FT80::1 as the IPv6 gateway address. Of course, in this router, I don't have access to configuration at that level, and perhaps the real problem in those examples is simply that they have a hard-coded Gateway address, which would keep the gateway address from the RA from being used, and perhaps it has nothing to do with using a link-local address for the gateway.
But this is looking like the link-local gateway address is being picked up from Comcast's RA when the connection is initially made, and then it's not being accepted from later RAs, and eventually, the gateway address is dropped off.
This sound familiar to anyone? Any ideas on how to fix it, other than waiting for Cisco to figure out the problem and send out an update?
