Is the IPv6 firewall built into the home routers safe?
The router that my ISP has delivered contains an IPv6 firewall. The only configuration option is whether it is on or off. Apparently, this firewall simply denies all incoming connections.
I understand this is to prevent exposing all hosts and all their open ports to the entire internet.
If I want to receive incoming IPv6 connections then I will need to disable this firewall.
Is it dangerous to disable it? I wonder if devices such as PCs and mobile devices are secure enough to be exposed to the internet. They certainly are supposed to be secure but are they secure in a practical sense?
My opinion is that it is not dangerous to disable the IPv6 firewall. But still, it is a bit unwise.
I have had since 2014 (if I recall right) directly connected IPv6 without any firewall at all, but there have never been any attempts using IPv6, even if the primary devices sit in the addresses ::1 and ::10. With IPv4 it happens all the time, trying SSH, trying HTTP vulnerabilities, trying common usernames and passwords etc. I use fail2ban, and additionally I route a bunch of large /12 ... /16 IPv4 blocks to /dev/null because they are useless for me. Without those the number of log rows from IPv4 attempts would be well above 100.000 per day. But as said, never anything with IPv6.
I am not saying that IPv6 attempts will not come. But I consider IPv6 much harder for hacking because of the trillion-size address space. If I would need to break into a /64 IPv6 subnet, I do not know where to start from. Perhaps I should first use some other means (fake phone call about support?) to find what equipment is in that destination, to be able to guess ranges of MAC addresses and the calculated IPv6 addresses, instead of randomly shooting the 2^64 block. Or concentrate on such vendor MAC addresses where the vendor is known to have certain vulnerabilities.