# dhcp(1)

    NAME
        dhcp - obtain network configuration via DHCP

    SYNOPSIS
        dhcp

    DESCRIPTION
        The DHCP client automatically obtains an IP address, subnet mask,
        default gateway, and other network parameters from a DHCP server
        on the local network using the Dynamic Host Configuration Protocol
        (RFC 2131).

        On success the network configuration is applied immediately via
        set_netcfg(). On failure the original configuration is restored.

        The client is run automatically by the init system at boot, but
        may also be invoked manually from the shell.

    PROTOCOL
        The client performs the standard four-message DHCP exchange:

            1. DHCPDISCOVER  Broadcast to 255.255.255.255:67
            2. DHCPOFFER     Server offers an IP address
            3. DHCPREQUEST   Client accepts the offered address
            4. DHCPACK       Server confirms the lease

        The BROADCAST flag (0x8000) is set so that server replies are
        sent to the broadcast address, since the client has no IP yet.

        Each step has a 10-second timeout. If no response is received
        the client exits with an error and restores the previous config.

    OUTPUT
        On success the client prints the assigned configuration:

            IP Address, Subnet Mask, Gateway, DNS Server, Lease Time

    OPTIONS
        The DHCP client requests the following options from the server:

            1   Subnet Mask
            3   Router (default gateway)
            6   DNS Server
            51  Lease Time

    SEE ALSO
        ifconfig(1), shell(1), syscalls(2)

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