10 patterns
Network & IP Regex Patterns
Network-related validation patterns for IP addresses, MAC addresses, CIDR blocks, and other networking primitives. Essential for infrastructure tools, firewall rule validation, and network configuration parsers.
Common Use Cases
All Network & IP Patterns
IPv4 Address
Validates IPv4 addresses (0.0.0.0 - 255.255.255.255).
^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$IPv4 with CIDR Notation
Validates IPv4 addresses with CIDR notation (e.g., 192.168.1.0/24).
^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\/(?:[0-9]|[1-2][0-9]|3[0-2])$MAC Address
Standard 48-bit MAC address (colon or hyphen separated).
^(?:[0-9A-Fa-f]{2}[:-]){5}(?:[0-9A-Fa-f]{2})$Port Number
Validates port numbers (1-65535).
^([1-9][0-9]{0,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])$MAC Address (Colon Format)
Validates MAC address in colon-separated format (AA:BB:CC:DD:EE:FF)
^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$IPv6 Address
Validates full and compressed IPv6 addresses.
^(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$|^::(?:[0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4}$|^[0-9a-fA-F]{1,4}::(?:[0-9a-fA-F]{1,4}:){0,5}[0-9a-fA-F]{1,4}$Hostname (Single Label)
Validates a single DNS hostname label (no dots, 1-63 characters).
^[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?$FQDN (Fully Qualified Domain Name)
Validates fully qualified domain names (hostname.domain.tld).
^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$IPv4 Subnet Mask
Validates IPv4 subnet masks (only valid octet values).
^(255|254|252|248|240|224|192|128|0)\.((255|254|252|248|240|224|192|128|0)\.){2}(255|254|252|248|240|224|192|128|0)$IPv4 with Port
Validates an IPv4 address with a port number (1–65535) in host:port form.
^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?):(?:[0-9]{1,4}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])$Frequently Asked Questions
What's the simplest IPv4 regex?
^(\d{1,3}\.){3}\d{1,3}$ - but this allows 999.999.999.999. For strict validation, use the full pattern that checks 0-255 ranges.
How do I validate an IPv6 address?
IPv6 has many valid formats including compressed notation (::1). Use the IPv6 Address pattern in the library.
What is a MAC address regex?
^([0-9a-fA-F]{2}[:-]){5}[0-9a-fA-F]{2}$ - accepts both colon and hyphen separators.
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