Configuring the tpid in vlan tags – H3C Technologies H3C S5560 Series Switches User Manual

Page 238

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Step

Command

Remarks

3.

Configure the port link type. port link-type { hybrid | trunk }

By default, the link type of
ports is access.

4.

Configure the port to allow
packets from its PVID and the

transparent VLANs to pass

through.

For hybrid ports:
port hybrid vlan vlan-id-list { tagged

| untagged }

For trunk ports:

port trunk permit vlan { vlan-id-list |

all }

By default, trunk ports allow
only packets from VLAN 1 to

pass through. Hybrid ports
allow only packets from

VLAN 1 to pass through

untagged.

5.

Enable QinQ on the port.

qinq enable

By default, QinQ is disabled.

6.

Specify transparent VLANs.

qinq transparent-vlan vlan-list

By default, transparent
transmission is not configured

for any VLANs on a port.

Configuring the TPID in VLAN tags

TPID identifies a frame as an 802.1Q tagged frame. The TPID value varies by vendor. On the 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, make sure the TPID setting is the same across all devices so 802.1Q

tagged frames can be identified correctly.
TPID settings include CVLAN TPID and SVLAN TPID.
A QinQ-enabled port uses the CLAN TPID to match incoming tagged frames. An incoming frame is

handled as untagged if its TPID is different from the CVLAN TPID.
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, a PE device is connected to a customer device that uses the TPID 0x8200 and to a provider

device that uses the TPID 0x9100. For correct packet processing, you must set the CVLAN TPID and

SVLAN TPID to 0x8200 and 0x9100 on the PE, respectively.
The TPID field 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 17

.

Table 17 Reserved EtherType values

Protocol type Value

ARP 0x0806

PUP 0x0200

RARP 0x8035

IP 0x0800

IPv6 0x86DD

PPPoE 0x8863/0x8864

MPLS 0x8847/0x8848

IPX/SPX 0x8137

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