Firewall/SOSDG 是一个基于 Netfilter/IPTables 的防火墙，主要特点是简单易用、功能还很强大，支持独立的服务器和路由器，支持NAT。

Changes:

1. 修复了 IPv6 DHCP 规则
2. Certain conn track rules were moved around, because they normally would not be used outside of a specific context.
3. 代码的清理以及bug修复