Topic: iptables: what does TPROXY a rule and what happens further?

Colleagues, the help with understanding iptables is necessary. Business happens on a router/rutere/rautere. There is a rule in the table mangle chain PREROUTING-A PREROUTING-i brlan0-p udp-m udp - dport 53-j TPROXY - on-port 3130 - on-ip - tproxy-mark 0x3/0xffffffff Tried to find in the Internet description TPROXY. Found, but a little that understood. ip rule: 0: from all lookup local 1: from all fwmark 0x3 lookup 100... 32767: from all lookup default ip route show table 100 local default dev lo scope host why there was a question. When I create a rule for lock DNS of packets in table FILTERING in chain FORWARD that DNS packets continue to walk. After digging, found out this rule. Now I try to understand why DNS packets jump.