100.98.21.128/26

Public

Class A — /26 prefix — 62 usable hosts

Network Address

100.98.21.128

Broadcast Address

100.98.21.191

Subnet Mask

255.255.255.192

Usable Hosts

First Usable IP

100.98.21.129

Last Usable IP

100.98.21.190

Total IPs

Prefix Length

/26

Network address — the base address of the block (100.98.21.128). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 100.98.21.191 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 62 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.255.255.192 is the dotted-decimal equivalent of /26. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation	100.98.21.128/26
Network Address	100.98.21.128
Broadcast Address	100.98.21.191
Subnet Mask	255.255.255.192
Wildcard Mask	0.0.0.63
Prefix Length	/26
IP Address Class	Class A
Total IP Addresses	64
Usable Host Addresses	62
First Usable IP	100.98.21.129
Last Usable IP	100.98.21.190
Network (Hex)	0x64621580
Broadcast (Hex)	0x646215BF
Address Type	Public / Globally Routable

Binary Representation

Network Address

01100100.01100010.00010101 01100100.01100010.00010101.10000000

Subnet Mask

11111111.11111111.11111111.11000000

The first 26 bits (1s in the mask) identify the network. The remaining 6 bits identify hosts within the network.

Split into Equal Subnets

Split 100.98.21.128/26 into 2 equal /27 subnets (30 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	100.98.21.128/27	100.98.21.128	100.98.21.129	100.98.21.158	100.98.21.159	30
2	100.98.21.160/27	100.98.21.160	100.98.21.161	100.98.21.190	100.98.21.191	30

Split 100.98.21.128/26 into 4 equal /28 subnets (14 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	100.98.21.128/28	100.98.21.128	100.98.21.129	100.98.21.142	100.98.21.143	14
2	100.98.21.144/28	100.98.21.144	100.98.21.145	100.98.21.158	100.98.21.159	14
3	100.98.21.160/28	100.98.21.160	100.98.21.161	100.98.21.174	100.98.21.175	14
4	100.98.21.176/28	100.98.21.176	100.98.21.177	100.98.21.190	100.98.21.191	14

Split 100.98.21.128/26 into 8 equal /29 subnets (6 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	100.98.21.128/29	100.98.21.128	100.98.21.129	100.98.21.134	100.98.21.135	6
2	100.98.21.136/29	100.98.21.136	100.98.21.137	100.98.21.142	100.98.21.143	6
3	100.98.21.144/29	100.98.21.144	100.98.21.145	100.98.21.150	100.98.21.151	6
4	100.98.21.152/29	100.98.21.152	100.98.21.153	100.98.21.158	100.98.21.159	6
5	100.98.21.160/29	100.98.21.160	100.98.21.161	100.98.21.166	100.98.21.167	6
6	100.98.21.168/29	100.98.21.168	100.98.21.169	100.98.21.174	100.98.21.175	6
7	100.98.21.176/29	100.98.21.176	100.98.21.177	100.98.21.182	100.98.21.183	6
8	100.98.21.184/29	100.98.21.184	100.98.21.185	100.98.21.190	100.98.21.191	6

Split 100.98.21.128/26 into 16 equal /30 subnets (2 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	100.98.21.128/30	100.98.21.128	100.98.21.129	100.98.21.130	100.98.21.131	2
2	100.98.21.132/30	100.98.21.132	100.98.21.133	100.98.21.134	100.98.21.135	2
3	100.98.21.136/30	100.98.21.136	100.98.21.137	100.98.21.138	100.98.21.139	2
4	100.98.21.140/30	100.98.21.140	100.98.21.141	100.98.21.142	100.98.21.143	2
5	100.98.21.144/30	100.98.21.144	100.98.21.145	100.98.21.146	100.98.21.147	2
6	100.98.21.148/30	100.98.21.148	100.98.21.149	100.98.21.150	100.98.21.151	2
7	100.98.21.152/30	100.98.21.152	100.98.21.153	100.98.21.154	100.98.21.155	2
8	100.98.21.156/30	100.98.21.156	100.98.21.157	100.98.21.158	100.98.21.159	2
9	100.98.21.160/30	100.98.21.160	100.98.21.161	100.98.21.162	100.98.21.163	2
10	100.98.21.164/30	100.98.21.164	100.98.21.165	100.98.21.166	100.98.21.167	2
11	100.98.21.168/30	100.98.21.168	100.98.21.169	100.98.21.170	100.98.21.171	2
12	100.98.21.172/30	100.98.21.172	100.98.21.173	100.98.21.174	100.98.21.175	2
13	100.98.21.176/30	100.98.21.176	100.98.21.177	100.98.21.178	100.98.21.179	2
14	100.98.21.180/30	100.98.21.180	100.98.21.181	100.98.21.182	100.98.21.183	2
15	100.98.21.184/30	100.98.21.184	100.98.21.185	100.98.21.186	100.98.21.187	2
16	100.98.21.188/30	100.98.21.188	100.98.21.189	100.98.21.190	100.98.21.191	2

IP Address Sample

Showing first 16 of 64 total IPs.

100.98.21.128 net

100.98.21.129

100.98.21.130

100.98.21.131

100.98.21.132

100.98.21.133

100.98.21.134

100.98.21.135

100.98.21.136

100.98.21.137

100.98.21.138

100.98.21.139

100.98.21.140

100.98.21.141

100.98.21.142

100.98.21.143

… 48 more IPs …

/26 Subnet Reference

Total IPs 64

Usable Hosts 62

Subnet Mask 255.255.255.192

Wildcard 0.0.0.63

Full /26 reference →

Related Ranges

Parent /25 block 100.98.21.128/25 Sibling /26 block 100.98.21.192/26

Adjacent Prefix Sizes

/24 254 hosts /25 126 hosts /26 62 hosts /27 30 hosts /28 14 hosts