Creating an Eth-Trunk Sub-interface
Context
If Layer 2 switching devices belong to different VLANs, and hosts in the VLANs need to communicate with each other, you need to create sub-interfaces on the Eth-Trunk connecting a Layer 3 device to a Layer 2 switching device, bind a VLAN to each sub-interface, and configure an IP address for each sub-interface.
After the configuration is complete, hosts in the VLANs can use these sub-interfaces to communicate with each other. Eth-Trunk sub-interfaces can be configured to terminate Dot1q and QinQ VLAN tags.
After Layer 2 Eth-Trunk sub-interfaces are configured, the Eth-Trunk provides Layer 2 functions and the sub-interfaces provide Layer 3 functions.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support Eth-Trunk sub-interfaces.
Procedure
- Run system-view
The system view is displayed.
- Run interface eth-trunk trunk-id
An Eth-Trunk is created and the Eth-Trunk interface view is displayed.
- Run quit
The system view is displayed.
- Run interface eth-trunk trunk-id.subnumber
An Eth-Trunk sub-interface is created.
subnumber specifies the number of a sub-interface. The value is in the range 1 to 4096.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support Ethernet sub-interfaces.
- Only hybrid and trunk interfaces on the preceding switches support Ethernet sub-interface configuration.
After you run the undo portswitch command to switch Layer 2 interfaces on the preceding series of switches into Layer 3 interfaces, you can configure Ethernet sub-interfaces on the interfaces.
After an interface is added to an Eth-Trunk, sub-interfaces cannot be configured on the interface.
- VLAN termination sub-interfaces cannot be created on a VCMP client.
- Run ip address ip-address { mask | mask-length } [ sub ]
An IP address is configured for the sub-interface.
When configuring multiple IP addresses for an Eth-Trunk sub-interface, specify the sub keyword.