~dig NS ga. +short
c.ns.ga.
a.ns.ga.
b.ns.ga.
d.ns.ga.
~dig
a.ns.ga.
b.ns.ga.
c.ns.ga.
d.ns.ga. +short
185.21.168.49
185.21.169.49
185.21.170.49
185.21.171.49
~time dig NS @
185.21.168.49
speed.ga.
^C
real 0m9.039s
user 0m0.011s
sys 0m0.011s
~# a fail
~time dig NS @
185.21.169.49
speed.ga.
^C
real 0m4.697s
user 0m0.009s
sys 0m0.020s
~#b fail
四个 NS 挂了俩。。这告诉我们一级域名的运营商也分三六九等
