我刚刚买了一个新路由器，价格相当昂贵（华硕 RT-AC66U）。我很快意识到，无论是 2.4GHz 还是 5GHz，无线连接都很糟糕。Mac 或 PC 的结果也类似。典型的 ping 会话如下所示（持续 2 分钟，间隔 1 秒）：
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=2.190 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=3.985 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=4.155 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=1.375 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.541 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=8.862 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=12.327 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=13.154 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=4.244 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=284.630 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=301.342 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=328.569 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=10.168 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=4.230 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1.207 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=19.310 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=4.040 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=4.059 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=4.233 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=1.642 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=1.593 ms
64 bytes from 192.168.1.1: icmp_seq=21 ttl=64 time=4.049 ms
64 bytes from 192.168.1.1: icmp_seq=22 ttl=64 time=4.223 ms
64 bytes from 192.168.1.1: icmp_seq=23 ttl=64 time=4.136 ms
64 bytes from 192.168.1.1: icmp_seq=24 ttl=64 time=1.277 ms
64 bytes from 192.168.1.1: icmp_seq=25 ttl=64 time=3.088 ms
64 bytes from 192.168.1.1: icmp_seq=26 ttl=64 time=4.268 ms
64 bytes from 192.168.1.1: icmp_seq=27 ttl=64 time=13.463 ms
64 bytes from 192.168.1.1: icmp_seq=28 ttl=64 time=4.167 ms
64 bytes from 192.168.1.1: icmp_seq=29 ttl=64 time=3.606 ms
64 bytes from 192.168.1.1: icmp_seq=30 ttl=64 time=2.931 ms
64 bytes from 192.168.1.1: icmp_seq=31 ttl=64 time=4.184 ms
64 bytes from 192.168.1.1: icmp_seq=32 ttl=64 time=4.071 ms
64 bytes from 192.168.1.1: icmp_seq=33 ttl=64 time=201.332 ms
64 bytes from 192.168.1.1: icmp_seq=34 ttl=64 time=218.367 ms
64 bytes from 192.168.1.1: icmp_seq=35 ttl=64 time=247.544 ms
64 bytes from 192.168.1.1: icmp_seq=36 ttl=64 time=57.321 ms
64 bytes from 192.168.1.1: icmp_seq=37 ttl=64 time=13.694 ms
64 bytes from 192.168.1.1: icmp_seq=38 ttl=64 time=3.918 ms
64 bytes from 192.168.1.1: icmp_seq=39 ttl=64 time=2.748 ms
64 bytes from 192.168.1.1: icmp_seq=40 ttl=64 time=1.839 ms
64 bytes from 192.168.1.1: icmp_seq=41 ttl=64 time=4.141 ms
64 bytes from 192.168.1.1: icmp_seq=42 ttl=64 time=3.919 ms
64 bytes from 192.168.1.1: icmp_seq=43 ttl=64 time=4.114 ms
64 bytes from 192.168.1.1: icmp_seq=44 ttl=64 time=1.316 ms
64 bytes from 192.168.1.1: icmp_seq=45 ttl=64 time=2.634 ms
64 bytes from 192.168.1.1: icmp_seq=46 ttl=64 time=10.943 ms
64 bytes from 192.168.1.1: icmp_seq=47 ttl=64 time=144.553 ms
64 bytes from 192.168.1.1: icmp_seq=48 ttl=64 time=158.767 ms
64 bytes from 192.168.1.1: icmp_seq=49 ttl=64 time=865.861 ms
64 bytes from 192.168.1.1: icmp_seq=50 ttl=64 time=1.009 ms
64 bytes from 192.168.1.1: icmp_seq=51 ttl=64 time=1.281 ms
64 bytes from 192.168.1.1: icmp_seq=52 ttl=64 time=1.199 ms
64 bytes from 192.168.1.1: icmp_seq=53 ttl=64 time=4.212 ms
64 bytes from 192.168.1.1: icmp_seq=54 ttl=64 time=1.714 ms
64 bytes from 192.168.1.1: icmp_seq=55 ttl=64 time=4.053 ms
64 bytes from 192.168.1.1: icmp_seq=56 ttl=64 time=21.046 ms
64 bytes from 192.168.1.1: icmp_seq=57 ttl=64 time=13.619 ms
64 bytes from 192.168.1.1: icmp_seq=58 ttl=64 time=14.630 ms
64 bytes from 192.168.1.1: icmp_seq=59 ttl=64 time=3.883 ms
64 bytes from 192.168.1.1: icmp_seq=60 ttl=64 time=4.119 ms
64 bytes from 192.168.1.1: icmp_seq=61 ttl=64 time=1.196 ms
64 bytes from 192.168.1.1: icmp_seq=62 ttl=64 time=4.048 ms
64 bytes from 192.168.1.1: icmp_seq=63 ttl=64 time=1.028 ms
64 bytes from 192.168.1.1: icmp_seq=64 ttl=64 time=1.116 ms
64 bytes from 192.168.1.1: icmp_seq=65 ttl=64 time=4.039 ms
64 bytes from 192.168.1.1: icmp_seq=66 ttl=64 time=16.272 ms
64 bytes from 192.168.1.1: icmp_seq=67 ttl=64 time=9.359 ms
64 bytes from 192.168.1.1: icmp_seq=68 ttl=64 time=29.070 ms
64 bytes from 192.168.1.1: icmp_seq=69 ttl=64 time=1.125 ms
64 bytes from 192.168.1.1: icmp_seq=70 ttl=64 time=3.871 ms
64 bytes from 192.168.1.1: icmp_seq=71 ttl=64 time=110.853 ms
64 bytes from 192.168.1.1: icmp_seq=72 ttl=64 time=131.584 ms
64 bytes from 192.168.1.1: icmp_seq=73 ttl=64 time=154.010 ms
64 bytes from 192.168.1.1: icmp_seq=74 ttl=64 time=1.178 ms
64 bytes from 192.168.1.1: icmp_seq=75 ttl=64 time=4.243 ms
64 bytes from 192.168.1.1: icmp_seq=76 ttl=64 time=9.988 ms
64 bytes from 192.168.1.1: icmp_seq=77 ttl=64 time=5.705 ms
64 bytes from 192.168.1.1: icmp_seq=78 ttl=64 time=19.701 ms
64 bytes from 192.168.1.1: icmp_seq=79 ttl=64 time=18.000 ms
64 bytes from 192.168.1.1: icmp_seq=80 ttl=64 time=3.954 ms
64 bytes from 192.168.1.1: icmp_seq=81 ttl=64 time=4.209 ms
64 bytes from 192.168.1.1: icmp_seq=82 ttl=64 time=1.173 ms
64 bytes from 192.168.1.1: icmp_seq=83 ttl=64 time=4.098 ms
64 bytes from 192.168.1.1: icmp_seq=84 ttl=64 time=3.956 ms
64 bytes from 192.168.1.1: icmp_seq=85 ttl=64 time=4.100 ms
64 bytes from 192.168.1.1: icmp_seq=86 ttl=64 time=16.471 ms
64 bytes from 192.168.1.1: icmp_seq=87 ttl=64 time=1.033 ms
64 bytes from 192.168.1.1: icmp_seq=88 ttl=64 time=4.681 ms
64 bytes from 192.168.1.1: icmp_seq=89 ttl=64 time=3.924 ms
64 bytes from 192.168.1.1: icmp_seq=90 ttl=64 time=4.040 ms
64 bytes from 192.168.1.1: icmp_seq=91 ttl=64 time=1.603 ms
64 bytes from 192.168.1.1: icmp_seq=92 ttl=64 time=1.626 ms
64 bytes from 192.168.1.1: icmp_seq=93 ttl=64 time=4.064 ms
64 bytes from 192.168.1.1: icmp_seq=94 ttl=64 time=3.708 ms
64 bytes from 192.168.1.1: icmp_seq=95 ttl=64 time=46.434 ms
Request timeout for icmp_seq 96
64 bytes from 192.168.1.1: icmp_seq=96 ttl=64 time=1104.146 ms
64 bytes from 192.168.1.1: icmp_seq=97 ttl=64 time=794.081 ms
64 bytes from 192.168.1.1: icmp_seq=98 ttl=64 time=1.135 ms
64 bytes from 192.168.1.1: icmp_seq=99 ttl=64 time=3.810 ms
64 bytes from 192.168.1.1: icmp_seq=100 ttl=64 time=3.683 ms
64 bytes from 192.168.1.1: icmp_seq=101 ttl=64 time=4.350 ms
64 bytes from 192.168.1.1: icmp_seq=102 ttl=64 time=4.148 ms
64 bytes from 192.168.1.1: icmp_seq=103 ttl=64 time=3.907 ms
64 bytes from 192.168.1.1: icmp_seq=104 ttl=64 time=3.768 ms
64 bytes from 192.168.1.1: icmp_seq=105 ttl=64 time=1.644 ms
64 bytes from 192.168.1.1: icmp_seq=106 ttl=64 time=7.536 ms
64 bytes from 192.168.1.1: icmp_seq=107 ttl=64 time=7.881 ms
64 bytes from 192.168.1.1: icmp_seq=108 ttl=64 time=3.987 ms
64 bytes from 192.168.1.1: icmp_seq=109 ttl=64 time=1.364 ms
64 bytes from 192.168.1.1: icmp_seq=110 ttl=64 time=1.251 ms
64 bytes from 192.168.1.1: icmp_seq=111 ttl=64 time=1.632 ms
64 bytes from 192.168.1.1: icmp_seq=112 ttl=64 time=4.191 ms
64 bytes from 192.168.1.1: icmp_seq=113 ttl=64 time=4.285 ms
64 bytes from 192.168.1.1: icmp_seq=114 ttl=64 time=3.966 ms
64 bytes from 192.168.1.1: icmp_seq=115 ttl=64 time=1.419 ms
64 bytes from 192.168.1.1: icmp_seq=116 ttl=64 time=108.544 ms
64 bytes from 192.168.1.1: icmp_seq=117 ttl=64 time=52.418 ms
64 bytes from 192.168.1.1: icmp_seq=118 ttl=64 time=3.854 ms
64 bytes from 192.168.1.1: icmp_seq=119 ttl=64 time=486.287 ms
--- 192.168.1.1 ping statistics ---
120 packets transmitted, 120 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.009/52.774/1104.146/159.580 ms
每隔 10-20 秒左右，连接就会严重下降。ping 时间可能会超过 1000 毫秒（并且经常出现数据包丢失），带宽从 70 MB/s 以上下降到几百 KB/s 的缓慢速度，有时甚至为 0（使用 iperf3 使用 TCP 和 UDP 进行测试）。
我尝试了所有方法。我尝试将 5GHz 接入点设置为仅 802.11ac，将 2.4GHz 接入点设置为仅 802.11n。我尝试了两个接入点的每个信道和信道宽度。我尝试禁用身份验证。我尝试安装最新固件，并尝试安装 DD-WRT。但都没有任何效果。
我突然想到这可能是外界干扰。我尝试将 MacBook 连接到启用了无线热点的手机。连接经常会像连接到路由器时一样降级。我还尝试连接到邻居的无线网络（2.4GHz）（当然是在他们允许的情况下），那里也发生了同样的情况。
我也用我弟弟的 Windows PC 确认了这一切，所以这不是我的 MacBook 的错。为了保险起见，我还尝试关闭公寓里的所有东西，包括我自己的路由器、电视、无线耳机和所有电脑。我还拔掉了微波炉和电视的插头。但没有任何效果。
有人知道可能发生了什么吗？似乎无论哪个设备连接到哪个其他设备，无线连接质量下降总是相同的。哪种家用设备会导致这种情况？我该怎么做才能找出原因？