可用系统：除了Windows、ArchLinux和Ubuntu都可以
免费计划有效期：目前看是一年，不知道续不续
IP段：刚才测试西雅图的段是 104.238.152.0/22
关于流量：
根据 https://www.vultr.com/resources/faq/#bandwidthhourly
Free bandwidth is allocated monthly. Each month you will receive a 2TB allotment of free bandwidth to use. There is no carryover of unused free bandwidth between months.
每个月2T免费流量
有新发现随时更新。
