CIDR /30 Subnet Reference

Minimal subnet — ideal for point-to-point WAN links. 2 usable hosts.

Subnet Mask255.255.255.252
Wildcard Mask0.0.0.3
Total IPs4
Usable Hosts2
Mask (Hex)FFFFFFFC
Host Bits2

Binary Breakdown

Subnet Mask11111111.11111111.11111111.11111100
Wildcard Mask00000000.00000000.00000000.00000011

Network bits (1s): 30 ·  Host bits (0s): 2

Common Uses for /30

  • Point-to-point link (2 hosts)
  • Router-to-router WAN link
  • Most efficient for P2P

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Enter any IP address with /30 prefix to calculate exact network details.

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Frequently Asked Questions

What is the subnet mask for /30?

The subnet mask for /30 is 255.255.255.252 (hex: FFFFFFFC). In binary: 11111111.11111111.11111111.11111100.

How many hosts does a /30 subnet support?

A /30 subnet has 4 total addresses. Subtract 2 (network + broadcast) = 2 usable host addresses.

What is the wildcard mask for /30?

The wildcard mask (inverse mask) for /30 is 0.0.0.3. Used in Cisco ACLs and OSPF configurations to match the host portion of an address.

What is CIDR /30 used for?

Point-to-point link (2 hosts). Router-to-router WAN link. Most efficient for P2P.

Complete CIDR Reference Table /0–/32

PrefixSubnet MaskWildcardTotal IPsUsable Hosts
/00.0.0.0255.255.255.2554.294.967.2964.294.967.294
/1128.0.0.0127.255.255.2552.147.483.6482.147.483.646
/2192.0.0.063.255.255.2551.073.741.8241.073.741.822
/3224.0.0.031.255.255.255536.870.912536.870.910
/4240.0.0.015.255.255.255268.435.456268.435.454
/5248.0.0.07.255.255.255134.217.728134.217.726
/6252.0.0.03.255.255.25567.108.86467.108.862
/7254.0.0.01.255.255.25533.554.43233.554.430
/8255.0.0.00.255.255.25516.777.21616.777.214
/9255.128.0.00.127.255.2558.388.6088.388.606
/10255.192.0.00.63.255.2554.194.3044.194.302
/11255.224.0.00.31.255.2552.097.1522.097.150
/12255.240.0.00.15.255.2551.048.5761.048.574
/13255.248.0.00.7.255.255524.288524.286
/14255.252.0.00.3.255.255262.144262.142
/15255.254.0.00.1.255.255131.072131.070
/16255.255.0.00.0.255.25565.53665.534
/17255.255.128.00.0.127.25532.76832.766
/18255.255.192.00.0.63.25516.38416.382
/19255.255.224.00.0.31.2558.1928.190
/20255.255.240.00.0.15.2554.0964.094
/21255.255.248.00.0.7.2552.0482.046
/22255.255.252.00.0.3.2551.0241.022
/23255.255.254.00.0.1.255512510
/24255.255.255.00.0.0.255256254
/25255.255.255.1280.0.0.127128126
/26255.255.255.1920.0.0.636462
/27255.255.255.2240.0.0.313230
/28255.255.255.2400.0.0.151614
/29255.255.255.2480.0.0.786
/30255.255.255.2520.0.0.342
/31255.255.255.2540.0.0.122
/32255.255.255.2550.0.0.011