How do you differentiate public and private IP addresses?
Zefrik
Member Posts: 8 ■□□□□□□□□□
in CCNA & CCENT
I am spending my summer studying for the CCNA exams and one of the things that has me stumped is private and public IP addresses. Here is a question as an example...
Which two of the following are private IP addresses?
A.) 12.0.0.1
B.) 168.172.19.39
C.) 172.20.14.36
D.) 172.33.194.30
E.) 192.168.24.43
I understand network classes (class A, B and C), and some of the different kinds of addresses (Broadcast, Unicast and Multicast) but I cannot find an explanation for public and private IP addresses.
Which two of the following are private IP addresses?
A.) 12.0.0.1
B.) 168.172.19.39
C.) 172.20.14.36
D.) 172.33.194.30
E.) 192.168.24.43
I understand network classes (class A, B and C), and some of the different kinds of addresses (Broadcast, Unicast and Multicast) but I cannot find an explanation for public and private IP addresses.
Comments
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E Double U
Member Posts: 2,233 ■■■■■■■■■■
C & E are the private addresses.
RFC 1918 private ranges:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
http://en.wikipedia.org/wiki/Private_networkAlphabet soup from (ISC)2, ISACA, GIAC, EC-Council, Microsoft, ITIL, Cisco, Scrum, CompTIA, AWS -
jvrlopez
Member Posts: 913 ■■■■□□□□□□
You just have to memorize the ranges.And so you touch this limit, something happens and you suddenly can go a little bit further. With your mind power, your determination, your instinct, and the experience as well, you can fly very high. ~Ayrton Senna
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cyberguypr
Mod Posts: 6,928 Mod
Take a peek at RFC 1918 - Address Allocation for Private Internets
https://tools.ietf.org/html/rfc1918 -
theodoxa
Member Posts: 1,340 ■■■■□□□□□□
You just have to memorize the ranges.
10.0.0.0/8
172.16.0.0/12
192.168.0.0/16
You just have to memorize these 3 networks and possibly 169.254.0.0/16, which is used for APIPA (Automatic Private IP Addressing).R&S: CCENT → CCNA → CCNP → CCIE [ ]
Security: CCNA [ ]
Virtualization: VCA-DCV [ ] -
theodoxa
Member Posts: 1,340 ■■■■□□□□□□
224.0.0.0 through 239.255.255.255 for multicast, also.
Class D (Multicast) -- 224.0.0.0/4
Class E ("Experimental") -- 240.0.0.0/4
[RANT] The sad thing is that half a billion IPv4 addresses were wasted on Class D (Multicast) and Class E (Experimental). That's 1/8th of the total address space. Very nearsighted of the folks who came up with the address classes. They didn't need anywhere near 256 million Multicast addresses and the experimental range (another 256 million addresses) sits largely unused while some regions exhaust their supply of IPv4 Addresses. [/RANT]R&S: CCENT → CCNA → CCNP → CCIE [ ]
Security: CCNA [ ]
Virtualization: VCA-DCV [ ]
