/17 Subnet
A /17 has 32,768 addresses, 32,766 of them usable by hosts. Its netmask is 255.255.128.0. Enter any address below to see its /17 network.
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Examples:
IPv4 network
32,766 usable hosts · 192.168.0.1 to 192.168.127.254
Details
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/17 at a glance
A /17 fixes the first 17 bits of the address as the network and leaves 15 bits for hosts, so it holds 2^15 = 32,768 addresses. The first is the network address and the last is the broadcast address, leaving 32,766 for hosts.
A /17 is 128 /24 networks side by side; registries and ISPs allocate blocks this size to networks that route them on the internet.
A /17 can be announced in BGP on its own: /24 is the longest prefix most networks accept.
Questions
How many usable IP addresses are in a /17?
What is the subnet mask for /17?
How many /24 networks are in a /17?
Is 255.255.128.0 the same as /17?
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