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以下是使用 nmap 工具扫描指定主机支持哪些 IP 协议（TCP、ICMP、IGMP等）的三个实例。nmap 工具可以上 http://insecure.org/nmap 网站下载。
一、
D:\Program Files\nmap-5.21>nmap -sO 192.168.1.12 | moreStarting Nmap 5.21 ( http://nmap.org ) at 2010-01-30 21:36 中国标准时间 Skipping IPProto Scan against 192.168.1.12 because Windows does not support scan ning your own machine (localhost) this way. Nmap scan report for 192.168.1.12 Host is up. PROTOCOL STATE SERVICE 0 unknown hopopt 1 unknown icmp 2 unknown igmp 3 unknown ggp 4 unknown ip 5 unknown st 6 unknown tcp 7 unknown cbt 8 unknown egp 9 unknown igp 10 unknown bbn-rcc-mon 11 unknown nvp-ii 12 unknown pup 13 unknown argus 14 unknown emcon 15 unknown xnet 16 unknown chaos 17 unknown udp 18 unknown mux 19 unknown dcn-meas 20 unknown hmp 21 unknown prm 22 unknown xns-idp 23 unknown trunk-1 24 unknown trunk-2 25 unknown leaf-1 26 unknown leaf-2 27 unknown rdp 28 unknown irtp 29 unknown iso-tp4 30 unknown netblt 31 unknown mfe-nsp 32 unknown merit-inp 33 unknown dccp 34 unknown 3pc 35 unknown idpr 36 unknown xtp 37 unknown ddp 38 unknown idpr-cmtp 39 unknown tp++ 40 unknown il 41 unknown ipv6 42 unknown sdrp 43 unknown ipv6-route 44 unknown ipv6-frag 45 unknown idrp 46 unknown rsvp 47 unknown gre 48 unknown mhrp 49 unknown bna 50 unknown esp 51 unknown ah 52 unknown i-nlsp 53 unknown swipe 54 unknown narp 55 unknown mobile 56 unknown tlsp 57 unknown skip 58 unknown ipv6-icmp 59 unknown ipv6-nonxt 60 unknown ipv6-opts 61 unknown anyhost 62 unknown cftp 63 unknown anylocalnet 64 unknown sat-expak 65 unknown kryptolan 66 unknown rvd 67 unknown ippc 68 unknown anydistribfs 69 unknown sat-mon 70 unknown visa 71 unknown ipcv 72 unknown cpnx 73 unknown cphb 74 unknown wsn 75 unknown pvp 76 unknown br-sat-mon 77 unknown sun-nd 78 unknown wb-mon 79 unknown wb-expak 80 unknown iso-ip 81 unknown vmtp 82 unknown secure-vmtp 83 unknown vines 84 unknown ttp 85 unknown nsfnet-igp 86 unknown dgp 87 unknown tcf 88 unknown eigrp 89 unknown ospfigp 90 unknown sprite-rpc 91 unknown larp 92 unknown mtp 93 unknown ax.25 94 unknown ipip 95 unknown micp 96 unknown scc-sp 97 unknown etherip 98 unknown encap 99 unknown anyencrypt 100 unknown gmtp 101 unknown ifmp 102 unknown pnni 103 unknown pim 104 unknown aris 105 unknown scps 106 unknown qnx 107 unknown a/n 108 unknown ipcomp 109 unknown snp 110 unknown compaq-peer 111 unknown ipx-in-ip 112 unknown vrrp 113 unknown pgm 114 unknown any0hop 115 unknown l2tp 116 unknown ddx 117 unknown iatp 118 unknown stp 119 unknown srp 120 unknown uti 121 unknown smp 122 unknown sm 123 unknown ptp 124 unknown isis-ipv4 125 unknown fire 126 unknown crtp 127 unknown crudp 128 unknown unknown 129 unknown unknown 130 unknown unknown 131 unknown unknown 132 unknown unknown 133 unknown unknown 134 unknown unknown 135 unknown unknown 136 unknown unknown 137 unknown unknown 138 unknown unknown 139 unknown unknown 140 unknown unknown 141 unknown unknown 142 unknown unknown 143 unknown unknown 144 unknown unknown 145 unknown unknown 146 unknown unknown 147 unknown unknown 148 unknown unknown 149 unknown unknown 150 unknown unknown 151 unknown unknown 152 unknown unknown 153 unknown unknown 154 unknown unknown 155 unknown unknown 156 unknown unknown 157 unknown unknown 158 unknown unknown 159 unknown unknown 160 unknown unknown 161 unknown unknown 162 unknown unknown 163 unknown unknown 164 unknown unknown 165 unknown unknown 166 unknown unknown 167 unknown unknown 168 unknown unknown 169 unknown unknown 170 unknown unknown 171 unknown unknown 172 unknown unknown 173 unknown unknown 174 unknown unknown 175 unknown unknown 176 unknown unknown 177 unknown unknown 178 unknown unknown 179 unknown unknown 180 unknown unknown 181 unknown unknown 182 unknown unknown 183 unknown unknown 184 unknown unknown 185 unknown unknown 186 unknown unknown 187 unknown unknown 188 unknown unknown 189 unknown unknown 190 unknown unknown 191 unknown unknown 192 unknown unknown 193 unknown unknown 194 unknown unknown 195 unknown unknown 196 unknown unknown 197 unknown unknown 198 unknown unknown 199 unknown unknown 200 unknown unknown 201 unknown unknown 202 unknown unknown 203 unknown unknown 204 unknown unknown 205 unknown unknown 206 unknown unknown 207 unknown unknown 208 unknown unknown 209 unknown unknown 210 unknown unknown 211 unknown unknown 212 unknown unknown 213 unknown unknown 214 unknown unknown 215 unknown unknown 216 unknown unknown 217 unknown unknown 218 unknown unknown 219 unknown unknown 220 unknown unknown 221 unknown unknown 222 unknown unknown 223 unknown unknown 224 unknown unknown 225 unknown unknown 226 unknown unknown 227 unknown unknown 228 unknown unknown 229 unknown unknown 230 unknown unknown 231 unknown unknown 232 unknown unknown 233 unknown unknown 234 unknown unknown 235 unknown unknown 236 unknown unknown 237 unknown unknown 238 unknown unknown 239 unknown unknown 240 unknown unknown 241 unknown unknown 242 unknown unknown 243 unknown unknown 244 unknown unknown 245 unknown unknown 246 unknown unknown 247 unknown unknown 248 unknown unknown 249 unknown unknown 250 unknown unknown 251 unknown unknown 252 unknown unknown 253 unknown unknown 254 unknown unknown 255 unknown unknown
Nmap done: 1 IP address (1 host up) scanned in 0.39 seconds
二、
D:\Program Files\nmap-5.21>nmap -sO 192.168.1.20 | moreStarting Nmap 5.21 ( http://nmap.org ) at 2010-01-30 21:44 中国标准时间 Nmap scan report for 192.168.1.20 Host is up (0.00s latency). All 256 scanned ports on 192.168.1.20 are open|filtered MAC Address: 00:1D:72:2E:F7:64 (Wistron)
Nmap done: 1 IP address (1 host up) scanned in 7.38 seconds
三、
D:\Program Files\nmap-5.21>nmap -sO 192.168.1.1 | moreStarting Nmap 5.21 ( http://nmap.org ) at 2010-01-30 21:45 中国标准时间 Nmap scan report for 192.168.1.1 Host is up (0.00s latency). Not shown: 255 open|filtered protocols PROTOCOL STATE SERVICE 1 open icmp MAC Address: 00:21:27:29:D0:F0 (Tp-link Technology Co.)
Nmap done: 1 IP address (1 host up) scanned in 6.42 seconds
第一与第二都是电脑，而第三个则是路由器。可见此路由器只支持一个ICMP协议。