Useful but Unknown Unix Tools: Calculating with IPs, The Sequel / / at 20:09 / / by abe

from the juggling-with-IPv6-netmasks dept.

This is a direct followup on my previous blog posting about calculating IPs and netmasks with the tools netmask and prips. Kurt Roeckx (via e-mail) and Niall Donegan (via a comment to that blog posting) both told me about the package sipcalc, and Kurt also mentioned the package ipcalc. Thanks for that! And since I found both useful, too, let’s put them in their own blog posting:

Both tools, ipcalc and sipcalc offer a “get all information at once” mode which are not present in the previously presented tool netmask.

ipcalc

ipcalc by default outputs all information and even in ANSI colors:

$ ipcalc 192.168.96.0/21 Address: 192.168.96.0 11000000 . 10101000 . 01100 000 . 00000000 Netmask: 255.255.248.0 = 21 11111111 . 11111111 . 11111 000 . 00000000 Wildcard: 0.0.7.255 00000000 . 00000000 . 00000 111 . 11111111 => Network: 192.168.96.0/21 110 00000 . 10101000 . 01100 000 . 00000000 HostMin: 192.168.96.1 11000000 . 10101000 . 01100 000 . 00000001 HostMax: 192.168.103.254 11000000 . 10101000 . 01100 111 . 11111110 Broadcast: 192.168.103.255 11000000 . 10101000 . 01100 111 . 11111111 Hosts/Net: 2046 Class C , Private Internet

(Coloured “Screenshots” done with ANSI HTML Adapter from the package aha.)

You can suppress the bitwise option or directly output HTML via commandline options. For example ipcalc -b -h 192.168.96.0/21 outputs the following content:

Address: 192.168.96.0 Netmask: 255.255.248.0 = 21 Wildcard: 0.0.7.255 => Network: 192.168.96.0/21 HostMin: 192.168.96.1 HostMax: 192.168.103.254 Broadcast: 192.168.103.255 Hosts/Net: 2046 Class C , Private Internet

Yes, that’s an HTML table and no preformatted text, just with a monospaced font. (I just removed the hardcoded text color from it, otherwise it would not look nice on dark backgrounds like in Planet Commandline’s default color scheme.)

Like netmask, ipcalc can also deaggregate IP ranges into largest possible networks:

$ ipcalc 192.168.87.0 - 192.168.110.255 deaggregate 192.168.87.0 - 192.168.110.255 192.168.87.0/24 192.168.88.0/21 192.168.96.0/21 192.168.104.0/22 192.168.108.0/23 192.168.110.0/24

( ipcalc -r 192.168.87.0 192.168.110.255 is just another way to write this, and it results in the same output.)

To find networks with at least 20, 63 and 30 IP addresses within a /24 network, use for example:

Address: 192.0.2.0 Netmask: 255.255.255.0 = 24 Wildcard: 0.0.0.255 => Network: 192.0.2.0/24 HostMin: 192.0.2.1 HostMax: 192.0.2.254 Broadcast: 192.0.2.255 Hosts/Net: 254 Class C 1. Requested size: 20 hosts Netmask: 255.255.255.224 = 27 Network: 192.0.2.128/27 HostMin: 192.0.2.129 HostMax: 192.0.2.158 Broadcast: 192.0.2.159 Hosts/Net: 30 Class C 2. Requested size: 63 hosts Netmask: 255.255.255.128 = 25 Network: 192.0.2.0/25 HostMin: 192.0.2.1 HostMax: 192.0.2.126 Broadcast: 192.0.2.127 Hosts/Net: 126 Class C 3. Requested size: 30 hosts Netmask: 255.255.255.224 = 27 Network: 192.0.2.160/27 HostMin: 192.0.2.161 HostMax: 192.0.2.190 Broadcast: 192.0.2.191 Hosts/Net: 30 Class C Needed size: 192 addresses. Used network: 192.0.2.0/24 Unused: 192.0.2.192/26

sipcalc

sipcalc is similar to ipcalc. One big difference seems to be the IPv6 support:

$ sipcalc 2001:DB8::/32 -[ipv6 : 2001:DB8::/32] - 0 [IPV6 INFO] Expanded Address - 2001:0db8:0000:0000:0000:0000:0000:0000 Compressed address - 2001:db8:: Subnet prefix (masked) - 2001:db8:0:0:0:0:0:0/32 Address ID (masked) - 0:0:0:0:0:0:0:0/32 Prefix address - ffff:ffff:0:0:0:0:0:0 Prefix length - 32 Address type - Aggregatable Global Unicast Addresses Network range - 2001:0db8:0000:0000:0000:0000:0000:0000 - 2001:0db8:ffff:ffff:ffff:ffff:ffff:ffff

(Thanks to Niall for the pointer to RFC3849. :-)

It can also split up networks into smaller chunks, but only same-size chunks, like e.g. split a /32 IPv6 network into /34 networks:

sipcalc -S34 2001:DB8::/32 -[ipv6 : 2001:DB8::/32] - 0 [Split network] Network - 2001:0db8:0000:0000:0000:0000:0000:0000 - 2001:0db8:3fff:ffff:ffff:ffff:ffff:ffff Network - 2001:0db8:4000:0000:0000:0000:0000:0000 - 2001:0db8:7fff:ffff:ffff:ffff:ffff:ffff Network - 2001:0db8:8000:0000:0000:0000:0000:0000 - 2001:0db8:bfff:ffff:ffff:ffff:ffff:ffff Network - 2001:0db8:c000:0000:0000:0000:0000:0000 - 2001:0db8:ffff:ffff:ffff:ffff:ffff:ffff -

Similar thing with IPv4:

sipcalc -s27 192.0.2.0/24 -[ipv4 : 192.0.2.0/24] - 0 [Split network] Network - 192.0.2.0 - 192.0.2.31 Network - 192.0.2.32 - 192.0.2.63 Network - 192.0.2.64 - 192.0.2.95 Network - 192.0.2.96 - 192.0.2.127 Network - 192.0.2.128 - 192.0.2.159 Network - 192.0.2.160 - 192.0.2.191 Network - 192.0.2.192 - 192.0.2.223 Network - 192.0.2.224 - 192.0.2.255

sipcalc also has a “show me all information” mode with the -a option:

$ sipcalc -a 192.168.96.0/21 -[ipv4 : 192.168.96.0/21] - 0 [Classfull] Host address - 192.168.96.0 Host address (decimal) - 3232260096 Host address (hex) - C0A86000 Network address - 192.168.96.0 Network class - C Network mask - 255.255.255.0 Network mask (hex) - FFFFFF00 Broadcast address - 192.168.96.255 [CIDR] Host address - 192.168.96.0 Host address (decimal) - 3232260096 Host address (hex) - C0A86000 Network address - 192.168.96.0 Network mask - 255.255.248.0 Network mask (bits) - 21 Network mask (hex) - FFFFF800 Broadcast address - 192.168.103.255 Cisco wildcard - 0.0.7.255 Addresses in network - 2048 Network range - 192.168.96.0 - 192.168.103.255 Usable range - 192.168.96.1 - 192.168.103.254 [Classfull bitmaps] Network address - 11000000.10101000.01100000.00000000 Network mask - 11111111.11111111.11111111.00000000 [CIDR bitmaps] Host address - 11000000.10101000.01100000.00000000 Network address - 11000000.10101000.01100000.00000000 Network mask - 11111111.11111111.11111000.00000000 Broadcast address - 11000000.10101000.01100111.11111111 Cisco wildcard - 00000000.00000000.00000111.11111111 Network range - 11000000.10101000.01100000.00000000 - 11000000.10101000.01100111.11111111 Usable range - 11000000.10101000.01100000.00000001 - 11000000.10101000.01100111.11111110 [Networks] Network - 192.168.96.0 - 192.168.103.255 (current)

Thanks again to Kurt and Niall for their contributions!

Now listening to the schreimaschine and fausttanz submissions for the interactive competition at the Bünzli/DemoDays in Olten (Switzerland)

