syns-last

$ tcpdump -n -r dump-20131110-013426-300s.pcap "tcp[tcpflags] & tcp-syn == tcp-syn" | cut -d' ' -f3 | cut -d'.' -f1-4 | sort | uniq -c | sort -g
      1 10.22.10.172
      1 10.22.11.55
      1 10.22.15.11
      1 10.22.19.102
      1 10.22.2.132
      1 10.22.21.50
      1 10.22.2.153
      1 10.22.26.100
      1 10.22.26.114
      1 10.22.26.141
      1 10.22.26.149
      1 10.22.3.104
      1 10.22.31.116
      1 10.22.37.69
      1 10.22.47.5
      1 10.22.48.104
      1 10.22.48.109
      1 10.22.48.135
      1 10.22.48.136
      1 10.22.48.165
      1 10.22.48.166
      1 10.22.48.169
      1 10.22.48.172
      1 10.22.48.173
      1 10.22.48.192
      1 10.22.51.117
      1 10.22.51.123
      1 10.22.58.100
      1 10.22.68.101
      1 10.22.68.13
      1 10.22.69.185
      1 10.22.69.253
      2 10.22.18.142
      2 10.22.19.103
      2 10.22.2.128
      2 10.22.24.9
      2 10.22.48.112
      2 10.22.48.141
      2 10.22.48.153
      2 10.22.48.185
      2 10.22.48.187
      2 10.22.48.191
      2 10.22.48.194
      2 10.22.59.42
      3 10.22.24.100
      3 10.22.44.81
      3 10.22.50.5
      3 10.22.68.36
      4 10.22.21.34
      4 10.22.2.187
      4 10.22.48.124
      4 10.22.48.134
      4 10.22.48.152
      4 10.22.48.163
      4 10.22.48.197
      4 10.22.68.98
      5 10.22.24.31
      5 10.22.26.121
      5 10.22.48.121
      5 10.22.48.130
      5 10.22.48.167
      5 10.22.48.183
      6 10.22.15.10
      6 10.22.26.138
      6 10.22.44.253
      6 10.22.47.124
      6 10.22.55.7
      7 10.22.10.160
      7 10.22.21.78
      7 10.22.48.113
      7 10.22.48.137
      7 10.22.48.186
      8 10.22.114.100
      8 10.22.24.30
      8 10.22.2.45
      8 10.22.48.126
      8 10.22.48.131
      9 10.22.48.118
      9 10.22.48.158
     10 10.22.48.123
     12 10.22.10.174
     12 10.22.48.108
     12 10.22.48.150
     12 10.22.48.168
     14 10.22.114.105
     14 10.22.48.122
     14 10.22.48.155
     14 10.22.48.160
     14 10.22.48.161
     14 10.22.48.180
     15 10.22.48.115
     15 10.22.48.116
     15 10.22.48.177
     16 10.22.48.138
     16 10.22.48.159
     18 10.22.48.120
     18 10.22.48.145
     18 10.22.48.162
     19 10.22.48.144
     19 10.22.48.198
     20 10.22.48.175
     21 10.23.1.1
     23 10.22.51.128
     23 10.22.69.36
     24 10.22.48.107
     25 10.22.48.184
     27 10.22.48.189
     28 10.22.48.170
     29 10.22.48.100
     29 10.22.48.117
     29 10.22.48.139
     30 10.22.48.195
     32 10.22.16.11
     33 10.22.48.119
     34 10.23.2.7
     36 10.22.37.10
     37 10.22.2.10
     37 10.22.48.157
     38 10.22.48.164
     39 10.22.48.149
     41 10.22.48.103
     41 10.22.48.133
     41 10.22.48.147
     42 10.22.48.110
     43 10.22.48.129
     43 10.22.48.182
     44 10.22.48.151
     45 10.22.59.5
     50 10.22.10.105
     54 10.23.2.1
     56 10.22.69.37
     57 10.22.48.190
     59 10.22.48.154
     59 10.22.48.181
     63 10.22.48.111
     65 10.23.2.3
     66 10.22.48.125
     70 10.22.26.158
     87 10.22.3.100
     92 10.22.2.43
     96 10.22.10.109
     96 10.22.31.106
     99 10.22.11.52
    109 10.22.23.3
    112 10.23.2.2
    124 10.23.2.8
    128 10.22.48.188
    130 10.22.31.52
    148 10.22.2.29
    159 10.22.3.102
    166 10.22.8.254
    182 10.22.47.7
    184 10.23.2.6
    232 10.22.10.10
    245 10.22.51.42
    286 10.23.0.3
    287 10.22.11.74
    302 10.22.40.1
    304 10.23.0.10
    344 10.23.0.4
    359 10.23.0.9
    452 10.23.2.4
    462 10.22.31.60
    463 10.22.48.105
    466 10.22.52.1
    466 10.22.55.1
    481 10.22.2.137
    512 10.22.28.114
    525 10.22.37.42
    561 10.22.0.1
    581 10.22.68.99
    612 10.22.114.101
    649 10.22.48.1
    680 10.22.29.1
    681 10.22.114.1
    685 10.22.6.1
    688 10.22.57.1
    706 10.22.112.1
    710 10.22.44.1
    750 10.22.2.1
    768 10.22.50.1
    771 10.22.16.12
    774 10.22.75.1
    809 10.23.0.5
    813 10.22.31.55
    814 10.22.8.1
    817 10.22.15.1
    837 10.22.22.1
    853 10.22.107.1
    853 10.22.99.1
    855 10.22.56.1
    856 10.22.58.1
    901 10.22.68.1
    909 10.22.75.254
    912 10.22.3.1
    922 10.22.105.1
    926 10.22.100.1
    927 10.22.37.70
    940 10.22.49.1
    962 10.22.47.1
    979 10.22.16.1
    988 10.22.59.1
   1003 10.22.19.1
   1008 10.22.26.1
   1010 10.22.20.1
   1014 10.22.28.1
   1029 10.22.25.1
   1062 10.22.81.1
   1077 10.22.24.1
   1077 10.22.4.1
   1078 10.22.32.1
   1084 10.22.33.1
   1090 10.22.69.1
   1109 10.22.10.1
   1111 10.22.37.1
   1119 10.22.23.1
   1125 10.22.11.1
   1138 10.22.31.1
   1167 10.23.2.5
   1187 10.22.64.1
   1196 10.22.51.1
   1222 10.22.4.128
   1257 10.22.18.1
   1275 10.22.21.1
   1338 10.22.54.1
   1452 10.22.105.22
   1532 10.22.19.2
   1548 10.22.26.111
   1588 10.22.112.100
   1811 10.22.22.254
   1963 10.22.114.103
   2121 10.22.68.42
   2657 10.22.26.107
   2704 10.22.24.34
   2946 10.22.47.4
   2988 10.22.69.35
   3041 10.22.32.161
   3271 10.22.74.1
   4312 10.22.69.45
   4366 10.22.44.9
   4684 10.22.21.46
   5321 10.22.6.131
   5510 10.22.44.82
   7257 10.22.26.105
   7300 10.22.29.254
   8983 10.22.81.2
   9020 10.22.7.1
  13191 10.22.48.2
  16285 10.23.0.1
 170060 10.22.6.13