Adding or Replacing a Customer VLAN for Q-in-Q Tunneling
With configuration of IPoE S-tag and C-Tag VLANs for Q-in-Q tunneling, the device can identify incoming untagged frames. It then adds both an S-tag (service VLAN or outer tag) and a C-tag (customer VLAN or inner tag) to each frame. Every port and every CPE is uniquely identified by a combination of the S-tag and C-tag. Similarly, the device can identify frames tagged with a common C-tag. Upon receipt of a tagged frame, the device adds the S-tag and replaces the common C-tag with a unique C-tag for each CPE. VLAN priority bits for Quality of Service (QoS) are preserved. For reverse traffic, the device replaces the unique C-tag with the original common C-tag for each frame before it reaches the CPE.
The following task enables a device to add or replace new CVLANs for Q-in-Q tunneling.
- Enter global configuration mode.
- Configure an Ethernet interface.
- Configure Q-in-Q tunneling and
add a replacement CVLAN. This example configures Q-in-Q tunneling for a specified CVLAN, adds a replacement CVLAN, and specifies a service VLAN to tunnel the CVLANs.
The following example configures Q-in-Q tunneling for a specified CVLAN, adds a replacement CVLAN, and specifies a service VLAN to tunnel the CVLANs.
device# configure terminal device(config)# interface ethernet 1/1/1 device(config-if-e1000-1/1/1)# qinq-tunnel cvlan 1 new-cvlan 2 svlan 4000
The following example shows information for Q-in-Q tunnels, including information for the replacement CVLAN.
device> show qinq-tunnel Total number of VLAN(s) tunneled: 2 Total number of HW resources used: 2 qinq enabled port(s): 1/1/1, 1/1/2 Port: 1/1/1 Number of CVLANs tunneled: 1 Service VLAN: 200 Original VLAN: None (Untagged) New CVLAN: 100 Port: 1/1/2 Number of CVLANs tunneled: 1 Service VLAN: 200 Original VLAN: 100 New CVLAN: 75