R0106-HP MSR Router Series Layer 2 - LAN Switching Configuration Guide(V7)

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Feature and hardware compatibility
QinQ is supported only on the HMIM 24GSW, HMIM 24GSW-PoE, and HMIM 8GSW interface
modules.
Restrictions and guidelines
The inner 802.1Q tag of QinQ frames is treated as part of payload. For correct transmission of QinQ
frames, HP recommends that you set the MTU of each interface to a minimum of 1504 bytes on the
service provider network. This value is the sum of the default Ethernet interface MTU (1500 bytes) and a
VLAN tag's size (4 bytes).
Enabling QinQ
Enable QinQ on customer-side ports of PEs. A QinQ-enabled port tags an incoming frame with its PVID.
To enable QinQ:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter Layer 2 Ethernet interface
view.
interface interface-type
interface-number
N/A
3. Enable QinQ.
qinq enable By default, QinQ is disabled.
Configuring the TPID for VLAN tags
TPID identifies a frame as an 802.1Q tagged frame. The TPID value varies by vendor. On an HP device,
the TPID in the 802.1Q tag added on a QinQ-enabled port is 0x8100 by default, in compliance with
IEEE 802.1Q. In a multi-vendor network, you must make sure the TPID setting is the same between directly
connected devices so 802.1Q tagged frames can be identified correctly.
TPID settings include CVLAN TPID and SVLAN TPID.
A QinQ-enabled port uses the CVLAN TPID to match incoming tagged frames. An incoming frame is
handled as untagged if its TPID is different from the CVLAN TPID.
The device supports only one CVLAN TPID globally.
SVLAN TPIDs are configurable on a per-port basis. A service provider-side port uses the SVLAN TPID to
replace the TPID in outgoing frames' SVLAN tags and match incoming tagged frames. An incoming
frame is handled as untagged if the TPID in its outer VLAN tag is different from the SVLAN TPID.
For example, the PE device is connected to a customer device that uses the TPID 0x8200 and to a
provider device that uses the TPID 0x9100. To be compatible with these devices, you must configure
0x8200 and 0x9100 as the CVLAN TPID and SVLAN TPID, respectively. The devices can then correctly
identify tagged frames.
The TPID in a tagged Ethernet frame is in the same position as the EtherType field in an untagged Ethernet
frame. To ensure correct packet type identification, do not set the TPID value to any of the values listed
in Table 9.