我想在我的机器上将所有来自eth2的GREstream量（IP协议47）转发到br0。 我怎样才能做到这一点？
我从来没有尝试过，但首先你需要匹配你想要的stream量。 你应该可以使用iptables和-p选项来使用协议号：
参数以下参数组成规则规范（如添加，删除，插入，replace和附加命令中所用的）。
[!] -p, --protocol protocol The protocol of the rule or of the packet to check. The speci‐ fied protocol can be one of tcp, udp, udplite, icmp, esp, ah, sctp or all, or it can be a numeric value, representing one of these protocols or a different one. A protocol name from /etc/protocols is also allowed. A "!" argument before the pro‐ tocol inverts the test. The number zero is equivalent to all. Protocol all will match with all protocols and is taken as default when this option is omitted.