Defining IP Interfaces using ifconfig

The ifconfig(1M) commands that are contained in the PPP configuration file establish the point-to-point (ipdptpn) and point-to-multipoint (ipdn) IP interfaces for Solstice PPP. These commands are executed when Solstice PPP is started, to assign a network address to each interface and to configure the network parameters.

Synopsis

The ifconfig commands used to establish the IP interfaces for Solstice PPP have the general form:

ifconfig interface plumb source [dest] netmask mask mtu mtu up

Arguments

interface

The name and type of the IP interface. The IP interfaces for Solstice PPP are ipdptpn (point-to-point) and ipdn (point-to-multipoint), where n is a number. By convention, IP interfaces are numbered sequentially from zero.

For example, ipdptp0, ipdptp1, ipdptp2, or ipd0, ipd1, ipd2

plumb

Opens the device associated with the interface name, and sets up the STREAMS that enable TCP/IP to use the device.

source

An IP address (dot notation) or hostname that represents the source address, or point of attachment, for point-to-point and point-to-multipoint IP interfaces.

dest

Point-to-point interfaces only. An IP address (dot notation) or hostname that represents the destination address for a point-to-point IP interface.

netmask mask

Specifies how much of the IP address to reserve for dividing networks into subnetworks. The mask can be entered in dot notation, or in hexadecimal when preceded by 0x.

mtu mtu

Sets the maximum transmission unit (MTU) for the interface. The MTU must be in the range 60 to 8232 bytes, and is usually set to 1500, which is the optimum value for Ethernet networks.

up

Marks the interface up--that is, active. You can disable an interface temporarily by marking it down. The IP interfaces associated with synchronous PPP links are usually marked up by default. If the IP interface associated with an asynchronous PPP link is marked up, the link manager will attempt to establish the link automatically when the IP layer passes an IP datagram to the interface.

Examples

To establish a point-to-multipoint IP interface for Solstice PPP, include an ifconfig command of the form:

ifconfig ipd0 plumb papyrus netmask 255.255.255.0 mtu 1500 up

To establish a point-to-point IP interface for Solstice PPP, include an ifconfig command of the form:

ifconfig ipdptp0 plumb
ifconfig ipdptp0 papyrus epic netmask 255.255.255.0 mtu 1500 up

Note that the interface can be fully defined by concatenating multiple ifconfig commands, as shown in the previous example.