Restrictions And Guidelines; Enabling Qinq; Configuring Transparent Transmission For Vlans - H3C S7500E-X Configuration Manual

Restrictions and guidelines

When you configure QinQ, follow these restrictions and guidelines:
•
Before you configure QinQ on a port, you must remove any VLAN mappings on the port. After
you enable QinQ on the port, you can configure all VLAN mapping types except two-to-two
VLAN mapping on it. If QinQ and a VLAN mapping conflict, the VLAN mapping takes effect.
•
The inner 802.1Q tag of QinQ frames is treated as part of the payload. As a best practice to
ensure correct transmission of QinQ frames, set the MTU to a minimum of 1504 bytes for each
port on the forwarding path. This value is the sum of the default Ethernet interface MTU (1500
bytes) and the length (4 bytes) of a VLAN tag.

Enabling QinQ

Enable QinQ on customer-side ports of PEs. A QinQ-enabled port tags an incoming frame with its
PVID.
To enable QinQ:
Step
Enter system view.
1.
Enter Layer 2 Ethernet
2.
interface view or Layer 2
aggregate interface view.
Enable QinQ.
3.

Configuring transparent transmission for VLANs

You can exclude a VLAN (for example, the management VLAN) from the QinQ tagging action on a
customer-side port. This VLAN is called a transparent VLAN.
To ensure successful transmission for a transparent VLAN, follow these configuration guidelines:
•
Set the link type of the port to trunk or hybrid, and assign the port to the transparent VLAN.
•
Do not configure any other VLAN manipulation actions for the transparent VLAN on the port.
•
Make sure all ports on the traffic path permit the transparent VLAN to pass through.
To enable transparent transmission for a list of VLANs:
Step
Enter system view.
1.
Enter Layer 2 Ethernet
2.
interface view or Layer 2
aggregate interface view.
Specify transparent VLANs.
3.
Command
system-view
interface interface-type
interface-number
qinq enable
Command
system-view
interface interface-type
interface-number
qinq transparent-vlan
vlan-id-list
191
Remarks
N/A
N/A
By default, QinQ is disabled.
Remarks
N/A
N/A
By default, transparent
transmission is not configured for
any VLANs on a port.