The default firewall state for IPv4 and IPv6 would be enabled. This can be disabled via the AAISP control pages. Rules can be added as required.
The firewall is configured via the router's Web interface:
Security -> Firewall -> Access Control
You don't need to create any special 'protocol' lists, you can simply enter in the Target IP/Port etc. in to the rule.
From the CLI the iptables command is available, which is familiar to Linux users. If logged in as supervisor the sh command is available to get a root shell prompt, where the ip6tables command can be found.
Having added a rule via the Web interface, it is worth checking with iptables or ip6tables that it has been successful - rules don't always get set correctly and/or may not survive a power cycle.