直接发工单问过，答复如下：
We ran into issues with IPv6 on KVM, this is the only feature that we are still not sure how to address. There are a few ways of implementing IPv6 on KVM; the most popular ones require using the host node as a gateway, which is not possible in our environment. We are still working on a possible solution.
基本意思就是 KVM 实现 IPv6 方法就几种，最常用的方法他们的环境不可用。感觉遥遥无期

搬瓦工中国直连线路+kcptun

@ntflc 对了， HG220G-U 破解很简单，网上一搜就有。主要思路就是拿到超级管理员账户，然后就可以进去把拨号改成桥接了，注意只改 INTERNET 那个，不要改其他的。