Example: Creating two VLANs

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest

VLANs are allocated in an existing interface that represents a physical Ethernet LAN.

The following example creates two VLANs, one with ID 3 and one with ID 5.

     ip addr add 198.51.160.23/19 dev ence400
     ip link set dev ence400 up
     ip link add dev ence400.3 link ence400 type vlan id 3
     ip link add dev ence400.5 link ence400 type vlan id 5

The ip link add commands added interfaces ence400.3 and ence400.5, which you can then configure:

     ip addr add  1.2.3.4/24    dev ence400.3
     ip link set dev ence400.3 up
     ip addr add  10.100.2.3/16 dev ence400.5
     ip link set dev ence400.5 up

The traffic that flows out of ence400.3 is in the VLAN with ID=3. This traffic is not received by other stacks that listen to VLANs with ID=4.

The internal routing table ensures that every packet to 1.2.3.x goes out through ence400.3 and everything to 10.100.x.x through ence400.5. Traffic to 198.51.1xx.x flows through ence400 (without a VLAN tag).

To remove one of the VLAN interfaces:

     ip link set dev ence400.3 down
     ip link delete ence400.3 type vlan