Cidr

net_cidr_to_mask¶

Convert a CIDR prefix length to a dotted-decimal subnet mask. Accepts the prefix with or without a leading slash (e.g. /24 or 24).

Example¶

net_cidr_to_mask 24   # => 255.255.255.0
net_cidr_to_mask /16  # => 255.255.0.0

Arguments¶

• $1 (string): CIDR prefix length, e.g. 24 or /24

Exit codes¶

• 0: Success
• 1: No valid argument supplied

Output on stdout¶

• The subnet mask in dotted-decimal notation

net_cidr_table¶

Print a table of all CIDR prefix lengths and their corresponding subnet masks, from /32 down to /0.

Exit codes¶

• 0: Always

Output on stdout¶

• Formatted table of prefix lengths and subnet masks

net_mask_to_cidr¶

Convert a dotted-decimal subnet mask to a CIDR prefix length. The mask must be a valid contiguous subnet mask (e.g. 255.255.255.0). Non-contiguous masks (e.g. 255.255.1.0) are rejected.

Example¶

net_mask_to_cidr 255.255.255.0   # => 24
net_mask_to_cidr 255.255.0.0     # => 16

Arguments¶

• $1 (string): Dotted-decimal subnet mask, e.g. 255.255.255.0

Exit codes¶

• 0: Success
• 1: Invalid or non-contiguous mask supplied

Output on stdout¶

• The CIDR prefix length as a plain integer

net_subnet_size¶

Print the total number of addresses in a subnet for a given CIDR prefix length. Accepts the prefix with or without a leading slash. Note: /32 = 1 address (host route); /31 = 2 addresses (point-to-point, RFC 3021); all others include network and broadcast addresses in the count.

Example¶

net_subnet_size 24   # => 256
net_subnet_size /16  # => 65536

Arguments¶

• $1 (string): CIDR prefix length, e.g. 24 or /24

Exit codes¶

• 0: Success
• 1: No valid argument supplied

Output on stdout¶

• Total address count as a plain integer

net_network_address¶

Derive the network address from an IP address and CIDR prefix. Accepts combined notation (ip/prefix) or two separate arguments.

Example¶

net_network_address 192.168.1.50/24   # => 192.168.1.0
net_network_address 10.0.3.7 8        # => 10.0.0.0

Arguments¶

• $1 (string): IP address with optional prefix (e.g. 192.168.1.50/24), or bare IP
• $2 (int): CIDR prefix length when not embedded in $1 (e.g. 24)

Exit codes¶

• 0: Success
• 1: Missing argument

Output on stdout¶

• Network address in dotted-decimal notation

net_broadcast_address¶

Derive the broadcast address from an IP address and CIDR prefix. Accepts combined notation (ip/prefix) or two separate arguments.

Example¶

net_broadcast_address 192.168.1.50/24   # => 192.168.1.255
net_broadcast_address 10.0.3.7 8        # => 10.255.255.255

Arguments¶

• $1 (string): IP address with optional prefix (e.g. 192.168.1.50/24), or bare IP
• $2 (int): CIDR prefix length when not embedded in $1 (e.g. 24)

Exit codes¶

• 0: Success
• 1: Missing argument

Output on stdout¶

• Broadcast address in dotted-decimal notation