If you are interested in seeing an instant snapshot of the traffic passing through your systems right now, the systat program on OpenBSD offers several useful views. One such view is the states view, which offers a live view of the state table. Here is a typical view:
3 users Load 2.38 2.34 2.25 (1-25 of 184) Sun Nov 28 19:07:57 2010 PR D SRC DEST STATE AGE EXP PKTS BYTES RATE PEAK AVG tcp I 192.168.103.84:51576 208.43.202.3:80 4:4 4984m 86369 12561 2199K 0 108 7 tcp O 213.187.179.198:5157 208.43.202.3:80 4:4 4984m 86369 12561 2199K 0 108 7 tcp I 192.168.103.254:5598 78.31.12.67:80 4:4 4570m 86373 22954 4781K 0 23 17 tcp O 213.187.179.198:5598 78.31.12.67:80 4:4 4570m 86373 22954 4781K 0 23 17 tcp I 10.168.103.15:3427 213.187.179.198:22 4:4 96162 86373 4784 705K 0 43 7 tcp I 10.168.103.15:22198 128.237.157.136:6667 4:4 26629 86385 6743 1918K 0 1677 73 tcp O 213.187.179.198:2219 128.237.157.136:6667 4:4 26629 86385 6743 1918K 0 1677 73 tcp I 10.168.103.15:19492 203.27.221.42:6667 4:4 26592 86385 2635 216K 0 34 8 tcp O 213.187.179.198:1949 203.27.221.42:6667 4:4 26592 86385 2635 216K 0 34 8 tcp I 10.168.103.15:4169 209.250.145.51:6667 4:4 26590 86385 2883 260K 0 40 10 tcp O 213.187.179.198:4169 209.250.145.51:6667 4:4 26590 86385 2883 260K 0 40 10 tcp I 10.168.103.15:29582 198.3.160.3:6667 4:4 26543 86385 2931 224K 0 34 8 tcp O 213.187.179.198:2958 198.3.160.3:6667 4:4 26543 86385 2931 224K 0 34 8 tcp I 10.168.103.15:26952 130.133.4.11:119 4:4 26340 86260 1015 522K 0 0 20 tcp O 213.187.179.198:2695 130.133.4.11:119 4:4 26340 86260 1015 522K 0 0 20 tcp I 192.168.103.254:6329 192.168.103.84:9000 4:4 26289 86376 29407 21M 0 6197 838 tcp O 192.168.103.1:53161 192.168.103.84:9000 4:4 26289 86376 29407 21M 0 6197 838 tcp I 10.168.103.15:28623 129.240.64.10:6667 4:4 25984 86385 3927 359K 0 32 14 tcp O 213.187.179.198:2862 129.240.64.10:6667 4:4 25984 86385 3927 359K 0 32 14 tcp I 10.168.103.15:4436 213.187.179.198:22 4:4 14349 86381 978 223K 0 56 15 icmp I 10.168.103.15:34372 213.187.179.198:8 0:0 11083 10 21716 1781K 168 168 164 tcp I 10.168.103.15:35760 194.14.70.181:80 4:4 10596 75806 143 114K 0 0 11 tcp O 213.187.179.198:3576 194.14.70.181:80 4:4 10596 75806 143 114K 0 0 11 tcp I 192.168.103.84:52785 74.125.77.188:5228 4:4 7877 85731 53 4833 0 0 0 tcp O 213.187.179.198:5278 74.125.77.188:5228 4:4 7877 85731 53 4833 0 0 0
Wider terminal windows offer more detail, and the OpenBSD version of systat offers several other PF-related views.