什么是lft？下面这是官方的解说

LFT, short for Layer Four Traceroute, is a sort of 'traceroute' that often works much faster (than the commonly-used Van Jacobson method) and goes through many configurations of packet-filters (firewalls).

就是一个比默认的traceroute更强大的工具，还可以显示AS号。官网为：lft

下面就是操作步骤

# 安装
[root@iZ8vb7it5p19lxlkj9a1y6Z ~]# yum install http://mirror.ghettoforge.org/distributions/gf/el/7/gf/x86_64/lft-3.73-1.gf.el7.x86_64.rpm

# 使用
[root@iZ8vb7it5p19lxlkj9a1y6Z ~]# lft -NAS 1.1.1.1
TTL LFT trace to one.one.one.one (1.1.1.1):80/tcp
 1  [AS?] [NULL] 10.247.219.30 0.7ms
 2  [749] [DODIIS] 11.73.16.21 1.1ms
 3  [749] [DODIIS] 11.95.21.81 1.0ms
 4  [AS?] [NULL] 10.102.35.117 1.4ms
 5  [AS?] [NULL] 10.54.254.209 4.8ms
 6  [AS?] [NULL] 10.102.155.98 5.8ms
 7  [23724] [CHINANET-BJ] 106.38.196.237 8.3ms
 8  [23724] [CHINANET-BJ] 36.110.246.229 7.7ms
 9  [4134] [CHINANET-BB] 202.97.94.234 25.3ms
**  [neglected] no reply packets received from TTL 10
11  [4134] [CHINANET-BB] 202.97.43.110 162.7ms
12  [4134] [CHINANET-US-POP] 218.30.53.214 160.3ms
13  [13335] [CLOUDFLARENET] 162.158.164.4 153.0ms
14  [13335] [APNIC-LABS] [target open] one.one.one.one (1.1.1.1):80 152.9ms