How to setup VLAN on same subnet as Ethernet

So this is what i'm trying to do:

I have a physical NIC with dev name eth0 with ip 192.168.1.2 and gateway 192.168.1.1 and I want to setup a VLAN with ip 192.168.1.x and same gateway as eth0.

Setting up the VLAN runs smoothly and i give the VLAN a iface name of eth0.10 and an ip of 192.168.1.69. Now when trying to establish a connection i get an error:

holmen@filserver:~$ sudo ifup eth0.10
Set name-type for VLAN subsystem. Should be visible in /proc/net/vlan/config
RTNETLINK answers: File exists
Failed to bring up eth0.10.

So how do I get the VLAN to connect to the internet and what does the error message mean? My guess s that it have something to do with the broadcast.

Please help!

Settings: /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp
        address 192.168.1.2
        netmask 255.255.255.0
        network 192.168.1.0
        gateway 192.168.1.1

iface eth0.10 inet static
        address 192.168.1.69
        netmask 255.255.255.0
        gateway 192.168.1.1

I have removed the auto eth0.10 since i dont want to establish it at startup

Settings: ifconfig

holmen@filserver:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:1a:4d:5b:02:5c
          inet addr:192.168.1.2  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::21a:4dff:fe5b:25c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11670807 errors:0 dropped:0 overruns:0 frame:0
          TX packets:22363842 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:833725090 (833.7 MB)  TX bytes:31876321312 (31.8 GB)
          Interrupt:44 Base address:0x4000

eth0.10   Link encap:Ethernet  HWaddr 00:1a:4d:5b:02:5c
          inet addr:192.168.1.69  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::21a:4dff:fe5b:25c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:432 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:41501 (41.5 KB)

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:16436  Metric:1
          RX packets:4899 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4899 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:697405 (697.4 KB)  TX bytes:697405 (697.4 KB)

Settings: netstat output

holmen@filserver:~$ netstat -anr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0          0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0.10

Test: ping output domain name

holmen@filserver:~$ ping -I eth0.10 www.dn.se
PING a1910.g1.akamai.net (23.60.69.161) from 192.168.1.2 eth0.10: 56(84) bytes of data.
From filserver.local (192.168.1.69) icmp_seq=1 Destination Host Unreachable
From filserver.local (192.168.1.69) icmp_seq=2 Destination Host Unreachable
From filserver.local (192.168.1.69) icmp_seq=3 Destination Host Unreachable
^C
--- a1910.g1.akamai.net ping statistics ---
5 packets transmitted, 0 received, +3 errors, 100% packet loss, time 4025ms
pipe 3

Test: ping output ip addr

holmen@filserver:~$ ping -I eth0.10 8.8.8.8
PING 8.8.8.8 (8.8.8.8) from 192.168.1.2 eth0.10: 56(84) bytes of data.
From 192.168.1.69 icmp_seq=1 Destination Host Unreachable
From 192.168.1.69 icmp_seq=2 Destination Host Unreachable
From 192.168.1.69 icmp_seq=3 Destination Host Unreachable
^C
--- 8.8.8.8 ping statistics ---
5 packets transmitted, 0 received, +3 errors, 100% packet loss, time 4023ms
pipe 3

Solution 1:

I believe the error message you're getting stems from trying to set the gateway twice. Your first "ifup" will work fine if you remove the gateway line from your interface file.

Besides that, what does any of this have to do with VLANs? What are you really trying to do?

Edit: I want to point out that when people say "VLAN" they are almost always talking about things like 802.11q tagging. It sounds like you meant to say something else.