Limpe o ip:
root@foo:~# ifconfig dummy0 192.168.55.1 netmask 255.255.255.0
root@foo:~# ifconfig dummy0
dummy0 Link encap:Ethernet HWaddr 5b:72:32:4f:92:c8
inet addr:192.168.55.1 Bcast:192.168.55.255 Mask:255.255.255.0
UP BROADCAST RUNNING NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
root@foo:~# ip address flush dev dummy0
root@foo:~# ifconfig dummy0 down
root@foo:~# ifconfig dummy0
dummy0 Link encap:Ethernet HWaddr 5b:72:32:4f:92:c8
BROADCAST NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)