Configuring Stack-vlan
Context
VLAN Switch is a forwarding method that forwards data according to the information in VLAN tags of received frames. This method requires a pre-configured static forwarding path along switching nodes on the network. When receiving VLAN-tagged frames matching VLAN Switch entries, a switching node forwards the frames to the interfaces manually specified in the VLAN Switch table. VLAN Switch improves device forwarding efficiency and security, and prevents MAC address attacks as well as broadcast storms.
Similar to the VLAN stacking function, the stack-vlan function adds outer VLAN tags to frames to implement communication within a VLAN across different ISP networks.
Procedure
- Run:
system-viewThe system view is displayed.
- Run:
vlan-switch vlan-switch-name interface interface-type interface-number vlan vlan-id1 [ to vlan-id2 ] interface interface-type interface-number [ stack-vlan vlan-id3 ]
Stack-vlan is configured to add outer VLAN tags.
VLAN Switch has the following requirements on interfaces:
The source and destination interfaces specified in the VLAN Switch configuration command must be hybrid or trunk interfaces, and cannot be access or Eth-Trunk member interfaces.
VLAN Switch has the following requirements on VLANs:
- The VLANs used in VLAN Switch cannot be created in the system view.
- The VLANs used in QinQ cannot be used by VLAN Switch.
- When an outer VLAN tag in double-tagged frames is used for VLAN stacking, VLAN mapping, or control VLAN, the VLAN tag cannot be used by VLAN Switch.
- SA cards of S series do not support stack-vlan.
- On a ring network, packets matching VLAN Switch entries can pass through the interfaces blocked by loop prevention protocols. Consequently, broadcast storms may occur. Therefore, VLAN Switch is not recommended for a ring network running a loop prevention protocol.
