关于移动 dns 劫持

坐标广东，猫是老光猫，只能在路由器上 pppoe 的
华为的，型号忘了
貌似一直劫持 53 端口，无论是 TCP 还是 UDP 的
随便找了一个 IP 去 tcping：
C:\Users\Administrator>tcping 31.13.75.17 53

Probing 31.13.75.17:53/tcp - Port is open - time=4.741ms
Probing 31.13.75.17:53/tcp - Port is open - time=1.608ms
Probing 31.13.75.17:53/tcp - Port is open - time=1.640ms
Probing 31.13.75.17:53/tcp - Port is open - time=1.330ms

Ping statistics for 31.13.75.17:53
4 probes sent.
4 successful, 0 failed. (0.00% fail)
Approximate trip times in milli-seconds:
Minimum = 1.330ms, Maximum = 4.741ms, Average = 2.330ms
nslookup：不通

然后我随便找了一个地址 lookup （注意，这个地址并非存在，尽管他是个内网地址）
C:\Users\Administrator>nslookup youtube.com 192.168.5.1
Server: UnKnown
Address: 192.168.5.1

Non-authoritative answer:
Name: youtube.com
Addresses: 2001::45ab:f714
31.13.74.1

居然通了？？？？？
114：
C:\Users\Administrator>nslookup youtube.com 114.114.114.114
Server: public1.114dns.com
Address: 114.114.114.114

Non-authoritative answer:
Name: youtube.com
Addresses: 2001::45ab:f714
31.13.80.1
第二个 114：
C:\Users\Administrator>nslookup youtube.com 114.114.114.115
DNS request timed out.
timeout was 2 seconds.
Server: UnKnown
Address: 114.114.114.115

Non-authoritative answer:
Name: youtube.com
Addresses: 2001::45ab:f714
31.13.80.1
不通
我不明白这个移动的 DNS 劫持究竟是在哪里进行的，看起来好象是在光猫那劫持