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How many IP address in 197.210.152.14/30

If im correct, its just 1 > 197.210.152.14 Gateway is 197.210.152.13

Ron Maupin
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Prince Nnamdi
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1 Answers1

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The /30 network that include the 197.210.152.14 IP address is 197.210.152.12/30

The /30 part indicate that there's 2 bits that define the host portion of the address (32-30 = 2). So you have 2^2 = 4 available IP addresses:

197.210.152.12
197.210.152.13
197.210.152.14
197.210.152.15

The first address of a subnet is reserved, it is the network address. The last address is also reserved, it is the broadcast address.

This leave you 2 usable addresses: 13 and 14. So you use one for your equipment and the other one is the ISP gateway address.

Note that, to avoid wasting IP addresses, a point to point link can be configured with a /31 network, in which there's only 2 addresses. This is an exception, defined in RFC3021 in which the addresses that are normally used for network and broadcast can be configured on hosts.

For information a point to point link can also be configured as unnumbered, in this case you route the traffic trough interface rather than IP.

JFL
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