examples:
ifconfig -au
[lists all up interfaces and settings]
ifconfig if0 release
[releases dhcp acquired address on interface 0]
ifconfig if1 dhcp dhcpMac 1234abcd persist
[enables dhcp on if1 for next boot and sets mac used in request]
ifconfig if2 169.254.0.4 netmask 255.255.0.0 add persist
[adds address/netmask to if2 and persists the change]
[if iterface was previously dhcp see notes above]
ifconfig if2 169.254.0.4 netmask ffff0000 gw 169.254.0.1 add
[adds default gateway to if2 but does not persist the change]
adapter Full name or pattern with '*' and '?' to 'match',
* matches any character, ? matches one character.
Options
/? Display this help message.
/all Display full configuration information.
/release Release the IP address for the specified adapter.
/renew Renew the IP address for the specified adapter.
/flushdns Purges the DNS Resolver cache.
/registerdns Refreshes all DHCP leases and re-registers DNS names
/displaydns Display the contents of the DNS Resolver Cache.
/showclassid Displays all the dhcp class IDs allowed for adapter.
/setclassid Modifies the dhcp class id.