CIDRinfo
The CIDRinfo table provides the means to map between different representations of subnets and subnet masks. This table belongs to the category mappings.
The following table describes the CIDRinfo table.
| Column name | Type |
Constraints | Description |
|---|---|---|---|
| maskBits | 32-bit integer | Primary key Not null |
The number of bits in the mask. For example, for a class C network, this is 24. |
| CIDRString | 7-character string | Not null | The Classless Inter-Domain Routing (CIDR) notation for the subnet. For example, for a class C network, this is /24. |
| inverseMask | IP Address | Not null | The inverse mask for the network. The inverse mask acts as a wildcard for OSPF and ACLs. |
| numHosts | 64-bit integer | Not null | The number of IP addresses in the network. For
example, for a class C network this is 256. |
| numClassC | Double precision floating point number | Not null | The number of class C networks within the subnet. |
| netmask | 15-character string | Not null | The subnet mask for the network. For example, for a class C network this is 255.255.255.0. |
The following table summarizes the information in the CIDRInfo table.
| Subnet mask | Bits | CIDR notation | Number of hosts |
|---|---|---|---|
| 0.0.0.0 | 0 | /0 | 4294967296 |
| 128.0.0.0 | 1 | /1 | 2147483648 |
| 192.0.0.0 | 2 | /2 | 1073741824 |
| 224.0.0.0 | 3 | /3 | 536870912 |
| 240.0.0.0 | 4 | /4 | 268435456 |
| 248.0.0.0 | 5 | /5 | 134217728 |
| 252.0.0.0 | 6 | /6 | 67108864 |
| 254.0.0.0 | 7 | /7 | 33554432 |
| 255.0.0.0 | 8 | /8 (A) | 16777216 |
| 255.128.0.0 | 9 | /9 | 8388608 |
| 255.192.0.0 | 10 | /10 | 4194304 |
| 255.224.0.0 | 11 | /11 | 2097152 |
| 255.240.0.0 | 12 | /12 | 1048576 |
| 255.248.0.0 | 13 | /13 | 524288 |
| 255.252.0.0 | 14 | /14 | 262144 |
| 255.254.0.0 | 15 | /15 | 131072 |
| 255.255.0.0 | 16 | /16 (B) | 65536 |
| 255.255.128.0 | 17 | /17 | 32768 |
| 255.255.192.0 | 18 | /18 | 16384 |
| 255.255.224.0 | 19 | /19 | 8192 |
| 255.255.240.0 | 20 | /20 | 4096 |
| 255.255.248.0 | 21 | /21 | 2048 |
| 255.255.252.0 | 22 | /22 | 1024 |
| 255.255.254.0 | 23 | /23 | 512 |
| 255.255.255.0 | 24 | /24 (C) | 256 |
| 255.255.255.128 | 25 | /25 | 128 |
| 255.255.255.192 | 26 | /26 | 64 |
| 255.255.255.224 | 27 | /27 | 32 |
| 255.255.255.240 | 28 | /28 | 16 |
| 255.255.255.248 | 29 | /29 | 8 |
| 255.255.255.252 | 30 | /30 | 4 |
| 255.255.255.254 | 31 | /31 | 2 |
| 255.255.255.255 | 32 | /32 | 1 |