Security becomes more and more important with growing Internet applications such as VoIP and e-commerce. Although IPv6 security can be constructed based on the existing IPSec or TLS, more considerations should be taken for IPv6 because IPv6 is an improvement rather than a derivation of IPv4. Besides, the security of IPv6-only mechanisms, such as stateless auto-configuration and transition mechanisms, is a new topic to consider. In this paper, we will introduce IPv6 related security issues with possible solutions and collect the existing IPv6 firewall products.