This is a helper module for VintageNet.Technology implementations that use IPv4.

IPv4 configuration is specified under the :ipv4 key in the configuration map. Fields include:

• :method - :dhcp, :static, or :disabled

The :dhcp method supports the following optional field:

• :dhcp_request_options - a list of additional DHCP option names (strings) to request from the DHCP server beyond udhcpc's defaults. Each entry is passed through to udhcpc as -O <entry>. Either symbolic names ("wpad", "sipsrv") or numeric option codes ("252") are accepted; what's recognized depends on the busybox version in use. Defaults to []. Values that the DHCP server returns are parsed by VintageNet.DHCP.Options and exposed via the ["interface", ifname, "dhcp_options"] property. Requesting additional options changes the contents of the DHCP request, which some networks use to classify or segment clients (for example, fingerprint-based VLAN assignment), so only opt in to options you actually need.

The :static method uses the following fields:

• :address - the IP address
• :prefix_length - the number of bits in the IP address to use for the subnet (e.g., 24)
• :netmask - either this or prefix_length is used to determine the subnet. If you have a choice, use prefix_length
• :gateway - the default gateway for this interface (optional)
• :name_servers - a list of DNS servers (optional)
• :domain - DNS search domain (optional)

Configuration normalization converts :netmask to :prefix_length.