rt, we can use eBPF’s <code>connect</code> program to process it, by modifying <code>user_ip</code> and <code>user_port</code>.</p><p>For the second part, we need to understand the concept of <code>ORIGINAL_DST</code> which belongs to the <code>netfilter</code> module in the kernel.</p><p>When an application (including Envoy) receives a connection, it will call the <code>get_sockopt</code> function to obtain <code>ORIGINAL_DST</code>. If going through the iptables <code>DNAT</code> process, iptables will 