VLAN tag with subinteface using linux.

[ha000049]

Hi everyone,

I have a question about an issue I faced during my university lab practice. Our professor gave us a topology with two switches connected to each other: two PCs are connected to the first switch using normal Ethernet connections, and another PC is connected to the second switch using a VLAN tag.

The task was to ping from the VLAN-tagged PC to one of the PCs connected with a normal Ethernet connection.

On my Linux system, I configured the VLAN interface using the following commands:

sudo ip link add link enp3s0 name enp3s0.10 type vlan id 10
sudo ip link set enp3s0.10 up
sudo ip addr add 192.168.x.x/24 dev enp3s0.10

However, the ping didn’t work, and I couldn’t figure out why.
Could you please help me understand what the problem might be?
btw In general I have creat a subinterface.

Note: I use port trunk and access port and both of them it doesnt work.

[Harold Ritter]

Hi @ha000049 ,

On the switch facing the workstation using a vlan tag, you need to configure the port as a trunk. You also need to configure vlan 10 manually.

[ha000049]

Hello @Harold Ritter 
Thank you for your reply. I tried that, but it still doesn’t work. I will share the simple topology and the commands I used, because I think I may have made a mistake when typing the commands. I had very little time in the lab and no access to hardware equipment, so I couldn’t properly identify where the mistake occurred.

Switch> enable

Switch# configure terminal

Switch(config)# vlan 10

Switch(config-vlan)# name VLAN10

Switch(config-vlan)# exit

! Access port for PC1 (VLAN10)

Switch1(config)# interface fastethernet0/1

Switch1(config-if)# switchport mode access

Switch1(config-if)# switchport access vlan 10

Switch1(config-if)# no shutdown

Switch1(config-if)# exit

! Trunk link to Switch2

Switch1(config)# interface fastethernet0/3

Switch1(config-if)# switchport mode trunk

Switch1(config-if)# switchport trunk allowed vlan 10

Switch1(config-if)# no shutdown

Switch1(config-if)# exit

and for SWITCH2:

Switch2(config)# interface fastethernet0/1

Switch2(config-if)# switchport mode access

Switch2(config-if)# switchport access vlan 10

Switch2(config-if)# no shutdown

! Trunk link to Switch1

Switch2(config)# interface fastethernet0/3

Switch2(config-if)# switchport mode trunk

Switch2(config-if)# switchport trunk allowed vlan 10,20

Switch2(config-if)# no shutdown

Switch2(config-if)# exit

and I changed to trunk mode for pc with vlan tag but it doesn t work, I used the same command as port trunk to switch 1 but identify the port that work toward pc! but nothing is working