netcalc is an advanced CLI-based network subnetting tool. It provides the following features:
- provided an ip address and mask, it will calculate the network address, broadcast address, bits in mask, and all hosts of the network
- provided an ip address, mask, and network count, it will calculate the network addresses, and masks in order to subnet the network into smaller networks based on the number of networks desired
- provided an ip address, mask, and host count, it will calculate the network addresses, and mask in ord to subnet the network into smaller networks based on the number of hosts desired
- provided an ip address, mask, and a list of host count values, it will calculate a list of VLSM subnets that match the list of host count requirements. Instead of making the subnets all the same size, it only creates enough subnets to match the list, and they may all be different sizes
- provided a list of subnets, it will try to summarize the subnets into one (or more) supernets if possible.
go test ./...
# running make will generate netcalc and netcalc-api in bin/
make
Netcalc is a IPv4/IPv6 network calculator
Usage:
netcalc [command]
Available Commands:
completion Generate the autocompletion script for the specified shell
help Help about any command
info Displays information about a network
subnet Given a network break it into smaller networks
summarize summarizes the networks provided to stdin
version Print the version number of netcalc
vlsm Given a network and comma-separated list of subnet lengths break it into smaller networks
Flags:
-h, --help help for netcalc
-j, --json Turns on JSON output for commands
-v, --verbose Turns on verbose output for commands
Use "netcalc [command] --help" for more information about a command.
Usage:
netcalc info <ip_address> <subnet_mask> [flags]
Flags:
-h, --help help for info
Global Flags:
-j, --json Turns on JSON output for commands
-v, --verbose Turns on verbose output for commands
> netcalc info 192.168.0.0 255.255.255.248 -v
Network: 192.168.0.0
Mask: 255.255.255.248 (/29)
Bcast: 192.168.0.7
192.168.0.1 255.255.255.248
192.168.0.2 255.255.255.248
192.168.0.3 255.255.255.248
192.168.0.4 255.255.255.248
192.168.0.5 255.255.255.248
192.168.0.6 255.255.255.248
Usage:
netcalc subnet [--hosts <hosts> | --networks <networks>] <ip_address> <subnet_mask> [flags]
Flags:
-h, --help help for subnet
--hosts int Specifies the number of hosts to include each subnet.
--networks int Specifies the number of subnets to create.
Global Flags:
-j, --json Turns on JSON output for commands
-v, --verbose Turns on verbose output for commands
> netcalc subnet --hosts 2 192.168.1.0 255.255.255.224
192.168.1.0 255.255.255.252
192.168.1.4 255.255.255.252
192.168.1.8 255.255.255.252
192.168.1.12 255.255.255.252
192.168.1.16 255.255.255.252
192.168.1.20 255.255.255.252
192.168.1.24 255.255.255.252
192.168.1.28 255.255.255.252
> netcalc subnet -v --hosts 2 192.168.1.0 255.255.255.224
* = assigned network
+ = useable network
[n] = # of useable hosts
__192.168.1.0/27
|__192.168.1.0/28
| |__192.168.1.0/29
| | |__192.168.1.0/30[2]+
| | |__192.168.1.4/30[2]+
| |__192.168.1.8/29
| | |__192.168.1.8/30[2]+
| | |__192.168.1.12/30[2]+
|__192.168.1.16/28
| |__192.168.1.16/29
| | |__192.168.1.16/30[2]+
| | |__192.168.1.20/30[2]+
| |__192.168.1.24/29
| | |__192.168.1.24/30[2]+
| | |__192.168.1.28/30[2]+
> netcalc subnet -j --hosts 2 192.168.1.0 255.255.255.248
{
"network": {
"address": "192.168.1.0",
"mask": "255.255.255.248",
"broadcast": "192.168.1.7"
},
"subnets": [
{
"network": {
"address": "192.168.1.0",
"mask": "255.255.255.252",
"broadcast": "192.168.1.3"
}
},
{
"network": {
"address": "192.168.1.4",
"mask": "255.255.255.252",
"broadcast": "192.168.1.7"
}
}
]
}
Usage:
netcalc vlsm <host_counts_list> <ip_address> <subnet_mask> [flags]
Flags:
-h, --help help for vlsm
Global Flags:
-j, --json Turns on JSON output for commands
-v, --verbose Turns on verbose output for commands
The subnet command above splits the network provided into a smaller of number of networks based on either host count or number of networks desired, all networks created have the same length subnet mask. The vlsm command also splits the network provided into a smaller number of networks but rather lets you provide a comma-separated list of host counts.
For example, for this example we start with 192.168.1.0 255.255.255.128 as our base network and have a need to subnet this further to support:
- Four (4) /30 point-to-point links (links between routers)
- Two (2) 20 host count networks (two small office networks)
You can accomplish this with netcalc by specifying the desired host count values as arguments to the command.
> netcalc vlsm 2,2,2,2,20,20 192.168.1.0 255.255.255.128
192.168.1.0 255.255.255.252
192.168.1.4 255.255.255.252
192.168.1.8 255.255.255.252
192.168.1.12 255.255.255.252
192.168.1.16 255.255.255.240
192.168.1.32 255.255.255.224
192.168.1.64 255.255.255.224
192.168.1.96 255.255.255.224
netcalc vlsm -v 2,2,2,2,20,20 192.168.1.0 255.255.255.128
* = assigned network
+ = useable network
[n] = # of useable hosts
__192.168.1.0/25
|__192.168.1.0/26
| |__192.168.1.0/27
| | |__192.168.1.0/28
| | | |__192.168.1.0/29
| | | | |__192.168.1.0/30[2]*
| | | | |__192.168.1.4/30[2]*
| | | |__192.168.1.8/29
| | | | |__192.168.1.8/30[2]*
| | | | |__192.168.1.12/30[2]*
| | |__192.168.1.16/28[14]+
| |__192.168.1.32/27[30]*
|__192.168.1.64/26
| |__192.168.1.64/27[30]*
| |__192.168.1.96/27[30]+
summarizes the networks provided to stdin
Usage:
netcalc summarize [flags]
Flags:
-h, --help help for summarize
Global Flags:
-j, --json Turns on JSON output for commands
-v, --verbose Turns on verbose output for command
The summarize command takes a list of networks from <stdin> and summarizes them at the bit level into a single summary network. This is useful for determining a common network route to configure in a routing environment to simplify routing advertisements.
In this example there is a text file (test/vlsm_networks.txt) containing the following networks:
192.168.1.0 255.255.255.252
192.168.1.4 255.255.255.252
192.168.1.8 255.255.255.252
192.168.1.12 255.255.255.252
192.168.1.16 255.255.255.240
192.168.1.32 255.255.255.224
192.168.1.64 255.255.255.224
192.168.1.96 255.255.255.224
> netcalc summarize < test/vlsm_networks.txt
192.168.1.0 255.255.255.128
The summarize command takes those networks and summarizes at the bit level to create the summary network of 192.168.1.0 255.255.255.128.
> curl http://localhost:3000/api/info?address=192.168.1.0&mask=255.255.255.0
{
"status": "ok",
"data": {
"address": "192.168.1.0",
"mask": "255.255.255.0"
}
}
> curl http://localhost:3000/api/subnet?address=192.168.1.0&mask=255.255.255.0&hostCount=60
{
"status": "ok",
"data": [
{
"address": "192.168.1.0",
"mask": "255.255.255.192"
},
{
"address": "192.168.1.64",
"mask": "255.255.255.192"
},
{
"address": "192.168.1.128",
"mask": "255.255.255.192"
},
{
"address": "192.168.1.192",
"mask": "255.255.255.192"
}
]
}
> curl http://localhost:3000/api/vlsm?address=192.168.1.0&mask=255.255.255.0&vlsmList=2,2,10
{
"status": "ok",
"data": [
{
"address": "192.168.1.0",
"mask": "255.255.255.252"
},
{
"address": "192.168.1.4",
"mask": "255.255.255.252"
},
{
"address": "192.168.1.8",
"mask": "255.255.255.248"
},
{
"address": "192.168.1.16",
"mask": "255.255.255.240"
},
{
"address": "192.168.1.32",
"mask": "255.255.255.224"
},
{
"address": "192.168.1.64",
"mask": "255.255.255.192"
},
{
"address": "192.168.1.128",
"mask": "255.255.255.128"
}
]
}
curl --location --request POST 'http://localhost:3000/api/summarize' \
--header 'Content-Type: application/json' \
--data-raw '[
{
"address": "192.168.1.0",
"mask": "255.255.255.252"
},
{
"address": "192.168.1.4",
"mask": "255.255.255.252"
},
{
"address": "192.168.1.8",
"mask": "255.255.255.252"
},
{
"address": "192.168.1.12",
"mask": "255.255.255.252"
}
]'
This is POST call and the raw body is a JSON array of network hashes (address and mask).