Áireamhán Folíon (IPv4 CIDR)
Miondealú iomlán IPv4 fo-ghréasáin: líonra, craoladh, masc, wildcard, raon óstach agus comhaireamh.
Torthaí a nuashonrú mar a chlóscríobh tú.
Maidir leis an áireamhán seo
This subnet calculator turns an IPv4 address and a CIDR prefix into the full structure of a subnet. An IPv4 address is 32 bits, usually written as four dot-separated octets like 192.168.1.10, and a CIDR prefix such as /24 splits those 32 bits into a network part (the leading bits, fixed for every host in the subnet) and a host part (the remaining bits, unique to each device). This calculator takes an address and a prefix length and derives the network address, broadcast address, subnet mask, wildcard mask and the range of usable host addresses, along with the IP class and total address count.
The size of a subnet is set by the prefix: a /n block holds 2^(32−n) addresses, of which two are reserved — the network address (all host bits 0, naming the subnet) and the broadcast address (all host bits 1, reaching every host). So a /24 has 2^8 = 256 addresses and 254 usable hosts, a /25 has 128 addresses and 126 usable hosts, and each extra prefix bit halves the block. As a worked example, 192.168.1.10/24 gives a network of 192.168.1.0, a broadcast of 192.168.1.255, a 255.255.255.0 mask, a 0.0.0.255 wildcard mask, and a usable host range of 192.168.1.1 to 192.168.1.254.
Subnetting is how networks are carved into manageable, secure segments — separating departments, sizing VLANs, planning address allocation and writing firewall and routing rules. The wildcard mask (the bitwise inverse of the subnet mask) is what Cisco access-control lists and OSPF use to match ranges of addresses. The /31 and /32 prefixes are special cases: /31 is used for point-to-point links with two usable addresses and no broadcast, and /32 describes a single host.
Ceisteanna Coitianta
Cé mhéad óstach atá i bhfoghréasán?
Tá 2^(32−n) seoladh ag foghréasán /n, lúide dhá cheann atá in áirithe don líonra agus don chraoladh.Tá 256 seoladh ag foghréasán /24 agus 254 óstríomhaire inúsáidte.
Cad is masc wildcard ann?
Is éard atá i masc wildcard ná an masc folíonra (255.0 → 0.255) a athrú go giotán ar giotán, agus úsáidtear é i liostaí rialaithe rochtana agus OSPF chun raonta seoltaí a mheaitseáil.
Cad é an difríocht idir líonra agus seoladh craolacháin?
Ainmníonn an seoladh líonra (gach giotán óstríomhaire 0) an foghréasán; sroicheann an seoladh craoltóireachta (gach giotán óstríomhaire 1) gach óstríomhaire air. Ní féidir an dá cheann a shannadh do ghléas.
Cad a chiallaíonn an réimír CIDR (/ 24, / 16)?
Is é an líon giotán tosaigh a chruthaíonn an chuid líonra den seoladh. Ciallaíonn réimír níos mó níos mó giotán líonra agus níos lú giotán óstach, mar sin foghréasán níos lú: tugann /24 254 óstach, tugann /25 126, agus gach giotán breise leathnaigh an bloc.
Conas is féidir liom a roinnt ar líonra i fo-líonraí níos lú?
Borrow host bits by increasing the prefix. Splitting a /24 into two /25s gives two blocks of 126 hosts; going to /26 gives four blocks of 62. Each added prefix bit doubles the number of subnets and halves their size.
Cad is aicme seoladh IP ann?
An scéim classful sean seoltaí scoilt ag a gcéad octet: Aicme A (1-126), Aicme B (128-191) agus Aicme C (192-223) le haghaidh unicast, móide D le haghaidh ilchasta agus E in áirithe. CIDR in ionad ranganna le haghaidh leithdháileadh, ach tuairiscíonn an t-áireamhán fós an aicme an seoladh thiteann i.
Cad iad / 31 agus / 32 foghréasáin a úsáidtear le haghaidh?
Tá /31 ach dhá sheoladh agus aon craoladh, a úsáidtear le haghaidh pointe-go-pointe naisc idir ródairí. Is /32 seoladh óstach amháin, coitianta le haghaidh loopbacks agus bealaí óstach. Láimhseálann an áireamhán an dá cásanna speisialta.
API — úsáid an áireamhán seo ó chód
Glaoigh ar an áireamhán seo mar chríochphointe JSON saor in aisce - níl aon eochair ag teastáil. Seol na luachanna réimse thíos mar pharaiméadair cheist nó JSON. Anything you omit uses the same default this page is pre-filled with; an unknown parameter is a 400, never a silent zero. Léigh an doiciméadú iomlán API →
Deireadhphointe
GET https://calculator.free/api/v1/subnet/curl
curl "https://calculator.free/api/v1/subnet/?ip=192.168.1.10&cidr=24"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/subnet/?" + new URLSearchParams({
"ip": "192.168.1.10",
"cidr": "24"
}));
const data = await r.json();
console.log(data.results);Is meastacháin iad na torthaí le haghaidh treoir ghinearálta amháin, ní comhairle airgeadais, leighis nó cánach.