What are the most important of firewall filter

I need any one have rules for filter firewall
that rules important for security
to show me a little of description of this rules

I recommend this page: http://wiki.mikrotik.com/wiki/Securing_your_router

You should make only exclusions you absolutely need and drop finally all three chains. But the most secure approach is not to connect anything anywhere. If you want some traffic to pass through, you have to make a compromise with the security always.

Thank you i will visit web later

Thank you for your Advice

The most important aspect of a firewall is that it is at the entry point of the networked system it protects. In the case of Packet Filtering, it is at the lowest level, or “layer” in the hierarchy (stack) of network processes, called the Network Layer or the Internet Layer. This means essentially that the firewall is the first program or process that receives and handles incoming network traffic, and it is the last to handle outgoing traffic.

Thank you for your Advice