Configuring Routed Interface and Sub-interface

Configuring Routed Interface

Step 1        Configure reserved VLAN for the use of routed interface.

    set vlans reserved-vlan <reserved-vlan>

Step 2         Enable Ethernet port as a layer 3 routed interface.

    set interface gigabit-ethernet <interface-name> routed-interface enable <true | false>

    set interface gigabit-ethernet <interface-name> routed-interface name <string>

Step 3         Run the following command to bring up the parent routed interface. Only after this, the corresponding sub-interfaces can be used normally.

     set l3-interface routed-interface <interface-name>

Step 4          Enable IP routing to perform layer 3 forwarding.

     set ip routing enable true

Step 5         Commit the configuration.

    commit

Configuring Sub-interface

Step 1        Configure the VLAN.

    set vlans vlan-id <vlan-id>

Step 2        Create sub-interface and configure its IP address.

    set interface gigabit-ethernet <interface-name> routed-interface sub-interface <sub-interface-name> vlan-id <vlan-id>

    set l3-interface routed-interface <interface-name> address <ip-address> prefix-length <prefix-number>

Step 3        Commit the configuration.

    commit

(Optional) Other Settings for Routed Interface and Sub-interface

Step 1        Configure the CPU egress rate limit for the routed interfaces and sub-interfaces.

    set l3-interface routed-interface <interface-name> rate-limit <rate-limit>

Step 2        Configure the MTU for the routed interfaces. It is not supported to configure MTU on the sub-interfaces. The sub-interfaces use the MTU value configured on the parent interface.

    set l3-interface routed-interface <interface-name> mtu <mtu-value>

Step 3        Bind the routed interface and sub-interface to the VRF.

    set l3-interface routed-interface <interface-name> vrf <vrf-name>

Step 4        Commit the configuration.

    commit

Checking the Configuration

• Run the command run show vlans routed-vlan to check the VLAN information of the routed interfaces and sub-interfaces.
• Run the command run show interface routed-interface brief to check the brief interface information of the routed interfaces and sub-interfaces.
• Run the command run show l3-interface routed-interface <interface-name> to check the detailed layer 3 interface information of a specific routed interface or sub-interface.