rt，以前只知道cernet ipv6会走hkix所以很快。今天试了一下ipv4，没想到延迟也很低，也是惊喜了 不知道原理是啥

traceroute 183.173.245.228traceroute to 183.173.245.228 (183.173.245.228), 30 hops max, 60 byte packets 1  192.168.200.1 (192.168.200.1)  5.448 ms  5.383 ms  5.332 ms 2  10.66.6.1 (10.66.6.1)  14.413 ms  14.381 ms  14.344 ms 3  ae11-1784.rt.eqx.hkg.cn.retn.net (87.245.241.0)  1.245 ms  1.185 ms  1.183 ms 4  * * * 5  101.4.114.181 (101.4.114.181)  37.874 ms  37.803 ms  37.772 ms 6  * * * 7  101.4.117.81 (101.4.117.81)  39.058 ms  35.863 ms  35.811 ms 8  101.4.115.145 (101.4.115.145)  35.520 ms 101.4.115.249 (101.4.115.249)  36.845 ms  36.723 ms 9  * * *10  xmn1.cernet.net (202.112.38.142)  35.765 ms  35.537 ms  35.503 ms11  118.229.4.74 (118.229.4.74)  36.735 ms  36.359 ms  36.629 ms12  * * *13  183.173.245.228 (183.173.245.228)  39.587 ms  39.899 ms  39.810 ms