I don't think you can force requests to be TCP in a Mikrotik router.
I can think of a couple of ways to sort your issue,
1. Run your own DNS resolver on a Linux box - you could even try metarouter. You may be able to force Bind9 to use TCP requests.
or
2. Find a friendly server not too distant from China (latency) and open a VPN tunnel to it then use the tunnel to access the Google DNS 8.8.8.8 etc. Add /32 routes to your Mikrotik pointing to the PPTP/SSTP/IPSEC tunnel for 8.8.8.8 and other server IP addresses.
regards
Andy
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Hi Andy / uksy29
Thank you for the suggestion!
Now I have to use the first program to use dnsforwarder (Chinese programmers write software), mandatory use tcp protocol to resolve.
The second program I originally used, but the low efficiency of this method after vpn, slower.
Originally, I was hoping to solve this problem directly RB751, but now it seems impossible.
Steven
19.DEC