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Calculadora de Sub-redes

Calcule o endereço de rede, o de broadcast, o intervalo de hosts e o número de hosts a partir de qualquer CIDR IPv4.

network192.168.1.0
broadcast192.168.1.255
mask255.255.255.0
firstHost192.168.1.1
lastHost192.168.1.254
hosts254
total256

Como usar esta ferramenta

  1. 1

    Type an IPv4 address with a prefix length into the box, for example 192.168.1.0/24. The field is pre-filled with that example to start.

  2. 2

    Read the results table as you type. The network and broadcast addresses, dotted-decimal subnet mask, first and last usable host, usable host count, and total address count appear immediately.

  3. 3

    Adjust the prefix length (the number after the slash) to widen or narrow the subnet and watch the host counts change.

  4. 4

    If you see an Invalid CIDR or Invalid IP message, fix the input. The prefix must be 0 to 32 and each of the four octets must be 0 to 255.

O que é a Calculadora de Sub-redes?

A notação CIDR (Classless Inter-Domain Routing) expressa uma sub-rede como IP/bits; por exemplo, 192.168.1.0/24 significa que os primeiros 24 bits identificam a rede, deixando 8 bits (256 endereços) para hosts. Esta ferramenta calcula tudo o que você precisa saber sobre uma sub-rede: endereço de rede, endereço de broadcast, intervalo de hosts utilizáveis e total de endereços.

Casos de uso comuns

  • Sizing a subnet for an office VLAN by checking how many usable hosts a /26 or /25 provides before you assign it.

  • Finding the network and broadcast addresses you must exclude when configuring a static DHCP address pool.

  • Translating a CIDR prefix into the dotted-decimal subnet mask a router or firewall interface expects, for example /22 to 255.255.252.0.

  • Confirming the usable host range when writing an access-control list or firewall rule for a specific subnet.

  • Verifying that a /31 point-to-point link between two routers gives you exactly two usable addresses with no broadcast waste.

  • Teaching or studying subnetting for a networking course or a CCNA exam by experimenting with prefixes and seeing host math update live.

Perguntas frequentes

O que são /31 e /32?
/31 é uma sub-rede de 2 endereços (enlaces ponto a ponto, sem broadcast). /32 é um único host.

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