ArpScanner

MAC-to-IP resolution + L2 IP-occupancy probe via Win32 SendARP P/Invoke. Used for Hyper-V VM IP discovery and flash-mikrotik MAC→IP resolution.

public static class ArpScanner

1. Methods

Scan UP IPv4 NIC subnets and return the IP that responds to ARP with the given MAC.

public static string FindIPByMAC(string targetMAC, string switchAdapterNamePattern = null)

Table 1. Parameters
Name	Type	Description
targetMAC	string	MAC in any common format (XX:XX:XX:XX:XX:XX or XX-XX-XX-XX-XX-XX).
switchAdapterNamePattern	string	Optional NIC name/description filter.

Returns: string

6-byte MAC → "XX:XX:XX:XX:XX:XX" uppercase.

public static string FormatMAC(byte[] macBytes)

Table 2. Parameters
Name	Type	Description
macBytes	byte[]

Returns: string

Robust L2 occupancy probe for ip. Uses SendARP (ignores ICMP-blocking firewalls) with a ping fallback. Retries 3x with 150 ms spacing.

public static bool IsIpOccupied(string ip)

Table 3. Parameters
Name	Type	Description
ip	string

Returns: bool

Any-format MAC → "XX:XX:XX:XX:XX:XX" uppercase.

public static string NormalizeMAC(string mac)

Table 4. Parameters
Name	Type	Description
mac	string

Returns: string