Facing the following situation when creating a virtual interface through a kernel module with name vlan1.1 and then assign an IP address to it. More specifically, when the virtual interface is alone and no other one is present with name vlan1.Y everything looks OK with ifconfig output. After performing the following steps I face the below strange output when issuing ifconfig:
Create vlan1.100 and assign an IP address to it 10.1.4.1/24
Create vlan1.1 and assign an IP address to it 192.168.1.1/24
vlan1.1 is shown twice with the second appearance not containing any statistics
vlan1.1 Link encap:Ethernet HWaddr 00:11:22:33:44:55 inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:7 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:738 (738.0 b)
vlan1.100 Link encap:Ethernet HWaddr 00:11:22:33:44:55 inet addr:10.1.4.1 Bcast:10.1.4.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:7 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:738 (738.0 b)
vlan1.1 Link encap:Ethernet HWaddr 00:11:22:33:44:55 inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Can you please inform me what could be the root cause of it? Please mind that ip link show shows each interface only once.