ipconfig8

Usage

Overview

ipconfig is a utility that communicates with the IPConfiguration agent to retrieve and set IP configuration parameters. It should only be used in a test and debug context. Using it for any other purpose is strongly discouraged. Public API's in the SystemConfiguration framework are currently the only supported way to access and control the state of IPConfiguration.

The IPConfiguration agent is responsible for configuring and managing the IPv4 and IPv6 addresses on direct, connectionless interfaces such as ethernet and Wi-Fi. The IPConfiguration agent is a program bundle that is loaded and executed by the configd(8) process.

The IPConfiguration agent implements the client side of the DHCP and BOOTP protocols described in RFC951, RFC1542, RFC2131, and RFC2132. It also assigns and maintains static IP addresses. It may also allocate and assign a link-local IP address if DHCP fails to acquire an IP address.

The IPConfiguration agent enables and controls the IPv6 SLAAC (RFC 4862) state in the kernel, and also handles statically configured IPv6 addresses. The agent implements the client side of the DHCPv6 protocol (RFC 3315) and supports both stateless and stateful operation.

In all cases, the IPConfiguration agent performs IP address conflict detection before assigning an IP address to an interface.

Commands

The ipconfig utility provides several commands:

waitall

Blocks until all network services have completed configuring, or have timed out in the process of configuring. This is only useful for initial system start-up time synchronization for legacy network services that are incapable of dealing with dynamic network configuration changes.

getifaddr interface-name

Prints to standard output the IP address for the first network service associated with the given interface. The output will be empty if no service is currently configured or active on the interface.

ifcount

Prints the number of interfaces that IPConfiguration is capable of configuring. The value that's printed will not change unless relevant network interfaces are either added to or removed from the system.

getoption interface-name (option-name | option-code)

Prints the BOOTP/DHCP option with the given name or option code integer value. See bootpd(8) for option code names. If an option has multiple values e.g. domain_name_server, only the first value is printed.

getpacket interface-name

Prints to standard output the DHCP/BOOTP packet that the client accepted from the DHCP/BOOTP server. This command is useful to check what the server provided, and whether the values are sensible. This command outputs nothing if DHCP/BOOTP is not active on the interface, or the attempt to acquire an IP address was unsuccessful.

getv6packet interface-name

Prints to standard output the latest DHCPv6 packet that the client accepted from the DHCPv6 server. In the case of stateful DHCPv6, it corresponds to the last packet from the server that contained addressing information. This command is useful to check what the server provided, and whether the values are sensible. This command outputs nothing if DHCPv6 is not active on the interface.

getra interface-name

Prints to standard output the latest IPv6 Router Advertisement packet that the client accepted from an advertising router. This command outputs nothing if no router is present.

getsummary interface-name

Prints to standard output a summary of the current IPConfiguration state over the specific interface.

getdhcpduid

Prints to standard output the DHCP DUID, if one has been established.

getdhcpiaid interface-name

Prints to standard output the DHCP IA_ID for the specific interface, if the interface is configured for IPv6 and the DHCP DUID has been established.

set interface-name NONE

set interface-name (DHCP | BOOTP)

set interface-name (MANUAL | INFORM) ip-address subnet-mask

set interface-name NONE-V6

set interface-name AUTOMATIC-V6

set interface-name MANUAL-V6 ipv6-address prefix-length

set interface-name 6TO4

Sets the interface to have a new temporary network service of the given type. Any existing services on the interface for the particular protocol (IPv4 or IPv6) are first de-configured before the new service is instantiated.

If NONE is specified, all existing IPv4 services are de-configured. If NONE-V6 is specified, all existing IPv6 services are de-configured.

DHCP and BOOTP require no additional arguments. The IP address, subnet mask, router, and DNS information are retrieved automatically.

Both MANUAL and INFORM require the specification of an IP address ip-address and a subnet mask subnet-mask.

The INFORM service configures the IP address statically like MANUAL, but then broadcasts DHCP INFORM packets to retrieve DHCP option information. If the DHCP server responds and supplies a subnet mask, that subnet mask is used instead of the specified subnet-mask.

AUTOMATIC-V6 requires no additional arguments. The IPv6 address, prefix length and router are retrieved automatically.

MANUAL-V6 requires the specification of the IPv6 address ipv6-address and a prefix length prefix-length.

6TO4 only works on Six To Four (IFT_STF) interfaces e.g. stf0. If it is specified on a non-IFT_STF interface, it has the same effect as specifying NONE-V6.

The set command requires root privileges.

Note: The set command is very useful for debugging, but it can't be used to configure a persistent service. The temporary services that are created only remain until the next network configuration change occurs. See scselect(8).

setverbose level

Enables or disables verbose mode logging in the IPConfiguration agent. Specify a level value of 0 to disable verbose logging, the default. Specify a value of 1 to enable verbose logging. This setting is persistent across boots of the operating system.

All logging generated by the IPConfiguration agent can be filtered using the "com.apple.IPConfiguration" subsystem identifier.

The setverbose command requires root privileges.

Examples

# ipconfig getpacket en0
op = BOOTREPLY
htype = 1
dp_flags = 0
hlen = 6
hops = 0
xid = 1956115059
secs = 0
ciaddr = 0.0.0.0
yiaddr = 192.168.4.10
siaddr = 192.168.4.1
giaddr = 0.0.0.0
chaddr = 0:3:93:7a:d7:5c
sname = dhcp.mycompany.net
file = 
options:
Options count is 10
dhcp_message_type (uint8): ACK 0x5
server_identifier (ip): 192.168.4.1
lease_time (uint32): 0x164a
subnet_mask (ip): 255.255.255.0
router (ip_mult): {192.168.4.1}
domain_name_server (ip_mult): {192.168.4.1}
domain_name (string): mycompany.net
end (none): 

# ipconfig getoption en0 router
192.168.4.1