10

There are a number of lists on the web that define all valid public ip addresses ranges but they don't seem to be very accurate.

The most common list Ive found is show below. This list however doesn't include addresses in 191.236.x.x even though there are public web servers in that range.

Is there a definitive and correct list?

  • 1.0.0.0 - 9.255.255.255
  • 11.0.0.0 - 126.255.255.255
  • 129.0.0.0 - 169.253.255.255
  • 169.255.0.0 - 172.15.255.255
  • 172.32.0.0 - 191.0.1.255
  • 192.0.3.0 - 192.88.98.255
  • 192.88.100.0 - 192.167.255.255
  • 192.169.0.0 - 198.17.255.255
  • 198.20.0.0 - 223.255.255.255
2
  • What has your research shown. The list you have isn't complete.
    – Ramhound
    Mar 17, 2016 at 2:08
  • 3
    Thats the point of the question
    – PeterJ
    Mar 24, 2016 at 21:45

4 Answers 4

12

IANA provides standards on this subject. For IPv4, here is what they have in their "special purpose address registry". Meaning, for our purposes, anything in these address blocks shouldn't be assigned because they shouldn't be routable "publicly".

0.0.0.0/8
10.0.0.0/8
100.64.0.0/10
127.0.0.0/8
169.254.0.0/16
172.16.0.0/12
192.0.0.0/24
192.0.0.0/29
192.0.0.8/32
192.0.0.9/32
192.0.0.170/32
192.0.0.171/32
192.0.2.0/24
192.31.196.0/24
192.52.193.0/24
192.88.99.0/24
192.168.0.0/16
192.175.48.0/24
198.18.0.0/15
198.51.100.0/24
203.0.113.0/24
240.0.0.0/4
255.255.255.255/32

# Also to be considered, multicast addresses subnet:
224.0.0.0/4

This is more consistent with the example you provided above.

If you don't understand CIDR notation, you can convert them to ranges here.

10
  • You forgot the multicast addresses, which, from a practical perspective, cannot be used on the Internet. 224.0.0.0/4.
    – Ron Maupin
    Mar 17, 2016 at 0:27
  • @RonMaupin That's true, thanks. I added that (as well as 239.0.0.0/8) to my post.
    – BrianC
    Mar 17, 2016 at 0:42
  • Also, there are IPv4 bogon lists which many ISPs use to block addresses from being routed on the Internet, e.g. team-cymru.org/Services/Bogons/fullbogons-ipv4.txt "A bogon prefix is a route that should never appear in the Internet routing table. A packet routed over the public Internet (not including over VPNs or other tunnels) should never have a source address in a bogon range."
    – Ron Maupin
    Mar 17, 2016 at 0:46
  • 3
    Thanks for the response but the point of question was to provide a reference for the valid ranges not the exclusions
    – PeterJ
    Mar 24, 2016 at 21:49
  • 1
    In the context of this question it doesn't make sense to list nets 192.0.0.0 with a bigger netmask than 24 here, because they are included in 192.0.0.0/24. The IANA list assignes special names for these subnets, so it makes sense there. But here it's just a list. Mar 19, 2019 at 16:40
3
  • 1.0.0.0-9.255.255.255
  • 11.0.0.0-100.63.255.255
  • 100.128.0.0-126.255.255.255
  • 128.0.0.0-169.253.255.255
  • 169.255.0.0-172.15.255.255
  • 172.32.0.0-191.255.255.255
  • 192.0.1.0/24
  • 192.0.3.0-192.88.98.255
  • 192.88.100.0-192.167.255.255
  • 192.169.0.0-198.17.255.255
  • 198.20.0.0-198.51.99.255
  • 198.51.101.0-203.0.112.255
  • 203.0.114.0-223.255.255.255
0

Combining the lists from BrianC and hmuller I figured that 3 ranges do overlap:

  • 192.31.196.0/24
  • 192.52.193.0/24
  • 192.175.48.0/24

In my combined list, they are considered as not valid:

CIDR             First IP      Last IP          
0.0.0.0/8        0.0.0.0       0.255.255.255    Not valid
                 1.0.0.0       9.255.255.255    Valid
10.0.0.0/8       10.0.0.0      10.255.255.255   Not valid
                 11.0.0.0      100.63.255.255   Valid
100.64.0.0/10    100.64.0.0    100.127.255.255  Not valid
                 100.128.0.0   126.255.255.255  Valid
127.0.0.0/8      127.0.0.0     127.255.255.255  Not valid
                 128.0.0.0     169.253.255.255  Valid
169.254.0.0/16   169.254.0.0   169.254.255.255  Not valid
                 169.255.0.0   172.15.255.255   Valid
172.16.0.0/12    172.16.0.0    172.31.255.255   Not valid
                 172.32.0.0    191.255.255.255  Valid
192.0.0.0/24     192.0.0.0     192.0.0.255      Not valid
192.0.1.0/24     192.0.1.0     192.0.1.255      Valid
192.0.2.0/24     192.0.2.0     192.0.2.255      Not valid
                 192.0.3.0     192.31.195.255   Valid
192.31.196.0/24  192.31.196.0  192.31.196.255   Not valid
                 192.31.197.0  192.52.192.255   Valid
192.52.193.0/24  192.52.193.0  192.52.193.255   Not valid
                 192.52.194.0  192.88.98.255    Valid
192.88.99.0/24   192.88.99.0   192.88.99.255    Not valid
                 192.88.100.0  192.167.255.255  Valid
192.168.0.0/16   192.168.0.0   192.168.255.255  Not valid
                 192.169.0.0   192.175.47.255   Valid
192.175.48.0/24  192.175.48.0  192.175.48.255   Not valid
                 192.175.49.0  198.17.255.255   Valid
198.18.0.0/15    198.18.0.0    198.19.255.255   Not valid
                 198.20.0.0    198.51.99.255    Valid
198.51.100.0/24  198.51.100.0  198.51.100.255   Not valid
                 198.51.101.0  203.0.112.255    Valid
203.0.113.0/24   203.0.113.0   203.0.113.255    Not valid
                 203.0.114.0   223.255.255.255  Valid
224.0.0.0/4      224.0.0.0     239.255.255.255  Not valid
240.0.0.0/4      240.0.0.0     255.255.255.255  Not valid
-1

All IP address from 1 to 191 excluding the RFC1918 private addresses below are assigned for Public IPs.:

RFC1918 - Private address alocation:

  • 10.0.0.0 - 10.255.255.255 (10/8 prefix)
  • 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
  • 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
1
  • 1
    Not all of them. (100.64.0.0/10 for example?) And the public allocations don't end at 191, they continue all the way to 223.
    – user1686
    Sep 19, 2018 at 14:29

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