ip6tables

Operating system: CentOS Linux 6.8

When I set up ip6tables (on Webmin): Webmin > Networking > Linux IPv6 Firewall

and I select the 5th option i.e. "Block all except SSH, IDENT, ping and high ports on interface: eth0," connecting to the server via SSH is failing over ipv6.

However, if I select the 4th option, or "Block all except SSH and IDENT on external interface: eth0," connecting to the server via SSH is successful over ipv6.

Why does the 5th option fail?