Appendix C. Lists of Reserved Ports, ICMP Types and Codes, and Internet Protocols

(130.234.250.64-130.234.250.95).

Class IP intervals

00-255

1

0-127

128-255

 

 

 

 

 

 

2

0-63

64-127

128-191

192-255

 

 

 

 

3

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

4

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

 

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

5

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

 

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

 

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

 

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

6

0-3

4-7

8-11

12-15

16-19

20-23

24-27

28-31

 

32-35

36-39

40-43

44-47

48-51

52-55

56-59

60-63

 

64-67

68-71

72-75

76-79

80-83

84-87

88-91

92-95

 

96-99

100-103

104-107

108-111

112-115

116-119

120-123

124-127

 

128-131

132-135

136-139

140-143

144-147

148-151

152-155

156-159

 

160-163

164-167

168-171

172-175

176-179

180-183

184-187

188-191

 

192-195

196-199

200-203

204-207

208-211

212-215

216-219

220-223

 

224-227

228-231

232-235

236-239

240-243

244-247

248-251

252-255

7

0-1

2-3

4-5

6-7

8-9

10-11

...

254-255

8

0

1

2

3

4

5

...

255

You could have a large network, for example 130.234.128.0/18, which is interpreted from the tables as all IP addresses from 130.234.128.0 to 130.234.191.255, inclusive (18 is in class no. 2, giving an IP interval of 128-191). N.B.: The netmask only reaches the third byte, which means that all IP addresses in byte 4 are available.

Reserved IP addresses

The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets (see also RFC 1918):

•10.0.0.0 - 10.255.255.255 (10/8)

•172.16.0.0 - 172.31.255.255 (172.16/12)

•192.168.0.0 - 192.168.255.255 (192.168/16)

345