DNAT:6                    net     loc:10.10.10.100:22 tcp 10100  -

Aug 17 00:02:55 m4789 kernel: [ 6809.163345] Shorewall:net_dnat:DNAT:IN=eth0 OUT= MAC=0c:c4:7a:99:0c:fc:28:99:3a:4d:23:91:08:00 SRC=217.88.84.61 DST=173.212.192.189 LEN=60 TOS=0x00 PREC=0

tcpdump -i eth0 port 10100 -n -Q inout
...
00:19:44.806518 IP 217.88.84.61.52464 > 173.212.192.189.10100: Flags [S], seq 4236641105, win 64240, options [mss 1452,sackOK,TS val 2752835732 ecr 0,nop,wscale 7], length 0