191.128.0.0/11

Public

Class B — /11 prefix — 2,097,150 usable hosts

Network Address

191.128.0.0

Broadcast Address

191.159.255.255

Subnet Mask

255.224.0.0

Usable Hosts

2,097,150

First Usable IP

191.128.0.1

Last Usable IP

191.159.255.254

Total IPs

2,097,152

Prefix Length

/11

Network address — the base address of the block (191.128.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 191.159.255.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 2,097,150 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.224.0.0 is the dotted-decimal equivalent of /11. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation	191.128.0.0/11
Network Address	191.128.0.0
Broadcast Address	191.159.255.255
Subnet Mask	255.224.0.0
Wildcard Mask	0.31.255.255
Prefix Length	/11
IP Address Class	Class B
Total IP Addresses	2,097,152
Usable Host Addresses	2,097,150
First Usable IP	191.128.0.1
Last Usable IP	191.159.255.254
Network (Hex)	0xBF800000
Broadcast (Hex)	0xBF9FFFFF
Address Type	Public / Globally Routable

Binary Representation

Network Address

10111111 10111111.10000000.00000000.00000000

Subnet Mask

11111111.11100000.00000000.00000000

The first 11 bits (1s in the mask) identify the network. The remaining 21 bits identify hosts within the network.

Split into Equal Subnets

Split 191.128.0.0/11 into 2 equal /12 subnets (1,048,574 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	191.128.0.0/12	191.128.0.0	191.128.0.1	191.143.255.254	191.143.255.255	1,048,574
2	191.144.0.0/12	191.144.0.0	191.144.0.1	191.159.255.254	191.159.255.255	1,048,574

Split 191.128.0.0/11 into 4 equal /13 subnets (524,286 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	191.128.0.0/13	191.128.0.0	191.128.0.1	191.135.255.254	191.135.255.255	524,286
2	191.136.0.0/13	191.136.0.0	191.136.0.1	191.143.255.254	191.143.255.255	524,286
3	191.144.0.0/13	191.144.0.0	191.144.0.1	191.151.255.254	191.151.255.255	524,286
4	191.152.0.0/13	191.152.0.0	191.152.0.1	191.159.255.254	191.159.255.255	524,286

Split 191.128.0.0/11 into 8 equal /14 subnets (262,142 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	191.128.0.0/14	191.128.0.0	191.128.0.1	191.131.255.254	191.131.255.255	262,142
2	191.132.0.0/14	191.132.0.0	191.132.0.1	191.135.255.254	191.135.255.255	262,142
3	191.136.0.0/14	191.136.0.0	191.136.0.1	191.139.255.254	191.139.255.255	262,142
4	191.140.0.0/14	191.140.0.0	191.140.0.1	191.143.255.254	191.143.255.255	262,142
5	191.144.0.0/14	191.144.0.0	191.144.0.1	191.147.255.254	191.147.255.255	262,142
6	191.148.0.0/14	191.148.0.0	191.148.0.1	191.151.255.254	191.151.255.255	262,142
7	191.152.0.0/14	191.152.0.0	191.152.0.1	191.155.255.254	191.155.255.255	262,142
8	191.156.0.0/14	191.156.0.0	191.156.0.1	191.159.255.254	191.159.255.255	262,142

Split 191.128.0.0/11 into 16 equal /15 subnets (131,070 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	191.128.0.0/15	191.128.0.0	191.128.0.1	191.129.255.254	191.129.255.255	131,070
2	191.130.0.0/15	191.130.0.0	191.130.0.1	191.131.255.254	191.131.255.255	131,070
3	191.132.0.0/15	191.132.0.0	191.132.0.1	191.133.255.254	191.133.255.255	131,070
4	191.134.0.0/15	191.134.0.0	191.134.0.1	191.135.255.254	191.135.255.255	131,070
5	191.136.0.0/15	191.136.0.0	191.136.0.1	191.137.255.254	191.137.255.255	131,070
6	191.138.0.0/15	191.138.0.0	191.138.0.1	191.139.255.254	191.139.255.255	131,070
7	191.140.0.0/15	191.140.0.0	191.140.0.1	191.141.255.254	191.141.255.255	131,070
8	191.142.0.0/15	191.142.0.0	191.142.0.1	191.143.255.254	191.143.255.255	131,070
9	191.144.0.0/15	191.144.0.0	191.144.0.1	191.145.255.254	191.145.255.255	131,070
10	191.146.0.0/15	191.146.0.0	191.146.0.1	191.147.255.254	191.147.255.255	131,070
11	191.148.0.0/15	191.148.0.0	191.148.0.1	191.149.255.254	191.149.255.255	131,070
12	191.150.0.0/15	191.150.0.0	191.150.0.1	191.151.255.254	191.151.255.255	131,070
13	191.152.0.0/15	191.152.0.0	191.152.0.1	191.153.255.254	191.153.255.255	131,070
14	191.154.0.0/15	191.154.0.0	191.154.0.1	191.155.255.254	191.155.255.255	131,070
15	191.156.0.0/15	191.156.0.0	191.156.0.1	191.157.255.254	191.157.255.255	131,070
16	191.158.0.0/15	191.158.0.0	191.158.0.1	191.159.255.254	191.159.255.255	131,070

/11 Subnet Reference

Total IPs 2,097,152

Usable Hosts 2,097,150

Subnet Mask 255.224.0.0

Wildcard 0.31.255.255

Full /11 reference →

Related Ranges

Parent /10 block 191.128.0.0/10 Sibling /11 block 191.160.0.0/11

Adjacent Prefix Sizes

/9 8,388,606 hosts /10 4,194,302 hosts /11 2,097,150 hosts /12 1,048,574 hosts /13 524,286 hosts