apparently something went wrong while writing the question, so here it is properly, my bad. Greetings, I have a host that has two vms, one is a router that all the machines on the network connect to it and that other a test virtual machine. the router vm is connected to the host using a virt net, the test virtual machine is connected to the router via a virtual switch. my /etc/network/interfaces defines vnet1 as dhcp by assuming that it is the vnet for the host (it was seen multiple times). yesterday I came back from a vacation, booted the system and didn't got any ip to the host, the rest of the machines on the network got ip. at the end, the issue was that vnet1 was the virtual switch rather than the host's virtual nic. is there a way for "lock" the vnics config so they won't change? the host is Debian 9.6, the output of ifconfig -a is below (the "faulty" scenario) dummy0 Link encap:Ethernet HWaddr C6:C8:2A:04:FD:23 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:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:22048 errors:0 dropped:0 overruns:0 frame:0 TX packets:22048 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1068960 (1.0 MiB) TX bytes:1068960 (1.0 MiB) virtsw0 Link encap:Ethernet HWaddr 52:54:00:6B:1B:92 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:92908 errors:0 dropped:0 overruns:0 frame:0 TX packets:18 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:13257095 (12.6 MiB) TX bytes:756 (756.0 B) virtsw0-nic Link encap:Ethernet HWaddr 52:54:00:6B:1B:92 BROADCAST MULTICAST 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:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) vnet0 Link encap:Ethernet HWaddr FE:54:00:8B:66:C1 inet addr:10.0.0.3 Bcast:10.0.0.255 Mask:255.255.255.0 inet6 addr: fe80::fc54:ff:fe8b:66c1/64 Scope:Link inet6 addr: fdab:9802:eb52:0:fc54:ff:fe8b:66c1/64 Scope:Global UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:528665 errors:0 dropped:0 overruns:0 frame:0 TX packets:752585 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:44311555 (42.2 MiB) TX bytes:2165654771 (2.0 GiB) vnet1 Link encap:Ethernet HWaddr FE:54:00:A7:79:6B inet6 addr: fe80::fc54:ff:fea7:796b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:92983 errors:0 dropped:0 overruns:0 frame:0 TX packets:81658 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:14566221 (13.8 MiB) TX bytes:4249914 (4.0 MiB) vnet2 Link encap:Ethernet HWaddr FE:54:00:54:78:BE inet6 addr: fe80::fc54:ff:fe54:78be/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:15 errors:0 dropped:0 overruns:0 frame:0 TX packets:257 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1962 (1.9 KiB) TX bytes:42261 (41.2 KiB) thanks, Dagg.