How to Display Interface Address Assignments

Routers and multihomed hosts have more than one interface and, often, more than one IP address assigned to each interface. You can use the ifconfig command to display all addresses that are assigned to the interfaces of a system. You can also use the ifconfig command to display only IPv4 or IPv6 address assignments. To additionally display the MAC addresses of the interfaces, you must first log in as superuser or assume the appropriate role.

For more information on the ifconfig command, see the ifconfig(1M) man page.

1. On the local system, assume the Network Management role or become superuser.

   Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services.

2. Obtain information about all interfaces.

   You can use variations of the ifconfig -a command to do the following:

   • View all addresses of all interfaces on the system.

     # ifconfig -a

   • View all IPv4 addresses that are assigned to a system's interfaces.

     # ifconfig -a4

   • If the local system is IPv6-enabled, display all IPv6 addresses that are assigned to a system's interfaces.

     ifconfig -a6

Example 4–2 Displaying Addressing Information for All Interfaces

This example shows entries for a host with solely a primary network interface, qfe0. Nevertheless, the ifconfig output shows that three forms of addresses are currently assigned to qfe0: loopback (lo0), IPv4 (inet), and IPv6 (inet6). In the IPv6 section of the output, note that the line for interface qfe0 displays the link-local IPv6 address. The second address for qfe0 is displayed on the qfe0:1 line.

% ifconfig -a
lo0: flags=1000849 <UP,LOOPBACK,RUNNING,MULTICAST,IPv4> mtu 8232 index 1
        inet 127.0.0.1 netmask ff000000 
qfe0: flags=1004843 <UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2 
        inet 10.0.0.112 netmask ffffff80 broadcast 10.0.0.127
        ether 8:0:20:b9:4c:54 
lo0: flags=2000849 <UP,RUNNING,MULTICAST,IPv6> mtu 8252 index 1
        inet6 ::1/128 
qfe0: flags=2000841 <UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 2
        ether 8:0:20:b9:4c:54 
        inet6 fe80::a00:20ff:feb9:4c54/10 
qfe0:1: flags=2080841 <UP,RUNNING,MULTICAST,ADDRCONF,IPv6> mtu 1500 index 2
        inet6 2001:db8:3c4d:48:a00:20ff:feb9:4c54/64 

Example 4–3 Displaying Addressing Information for All IPv4 Interfaces

This example shows the IPv4 address that is configured for a multihomed host. You do not need to be logged in as superuser to run this form of the ifconfig command.

% ifconfig -a4
lo0: flags=1000849 <UP,LOOPBACK,RUNNING,MULTICAST,IPv4> mtu 8232 index 1
        inet 127.0.0.1 netmask ff000000
qfe0: flags=1004843 <UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
        inet 10.0.0.112 netmask ffffff80 broadcast 10.0.0.127
        ether 8:0:20:b9:4c:54 
qfe1: flags=1004843 <UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
        inet 10.0.0.118 netmask ffffff80 broadcast 10.0.0.127
        ether 8:0:20:6f:5e:17

Example 4–4 Displaying Addressing Information for All IPv6 Interfaces

This example shows only the IPv6 addresses that are configured for a particular host. You do not need to be logged in as superuser to run this form of the ifconfig command.

% ifconfig -a6
lo0: flags=2000849 <UP,LOOPBACK,RUNNING,MULTICAST,IPv6> mtu 8252 index 1
        inet6 ::1/128 
qfe0: flags=2000841 <UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 2
        ether 8:0:20:b9:4c:54 
        inet6 fe80::a00:20ff:feb9:4c54/10
qfe0:1: flags=2080841 <UP,RUNNING,MULTICAST,ADDRCONF,IPv6> mtu 1500 index 2
        inet6 2001:db8:3c4d:48:a00:20ff:feb9:4c54/64 

This output from ifconfig shows the following three types of IPv6 address forms that are assigned to the single interface of a host:

lo0

IPv6 loopback address.

inet6 fe80::a00:20ff:feb9:4c54/10

Link-local address that is assigned to the primary network interface.

inet6 2001:db8:3c4d:48:a00:20ff:feb9:4c54/64

IPv6 address, including subnet prefix. The term ADDRCONF in the output indicates that this address was autoconfigured by the host.