Problems with IPv6 firewall and connecting devices
I have a 3rd generation Time Capsule....Over a year ago, I started having a lot of problems with wi-fi devices dropping from the network. At the time, I thought it was because my neighborhood was overly saturated with wi-fi signals. I've had much better luck with 5ghz networks, but some of the older devices in the house don't support 5GHz wifi.
Anyway, I just resurrected a couple of older machines - an old smartphone (android) and an old laptop (windows 7). Neither device was able to connect to the network at all. Both indicated authentication problems.
I started trying a couple of things with the settings on the time capsule, and it turns out that removing the IPv6 firewall (unchecking 'Block IPv6 incoming connections' under Network > Network Options) seems to allow these devices to connect. I have tested it, and everytime I re-enable the firewall, the devices stop connecting.
I have two questions:
1) Does this behavior make sense to anyone?
2) Is it a huge security risk to leave 'Block IPv6 incoming connections' unchecked?
As some additional information, I generally haven't had many problems with newer devices connecting (even to the 2.4GHz network). Also, if it's helpful at all, the TC is connected to a cable modem (RCN is the provider).
Any insight/assistance would be greatly appreciated. Thanks!!!