H3C S5500-SI Series User manual

Operation Manual – QinQ-BPDU TUNNEL
H3C S5500-SI Series Ethernet Switches Table of Contents
i
Table of Contents
Chapter 1 QinQ Configuration ..................................................................................................... 1-1
1.1 Introduction to QinQ...........................................................................................................1-1
1.1.1 Understanding QinQ ...............................................................................................1-1
1.1.2 Implementations of QinQ ........................................................................................1-2
1.1.3 Modification of TPID Value of QinQ Frames...........................................................1-2
1.2 Configuring Basic QinQ.....................................................................................................1-4
1.3 Configuring Selective QinQ ...............................................................................................1-4
1.4 Configuring the TPID Value to Be Carried in VLAN Tags ................................................. 1-5
1.5 QinQ Configuration Example.............................................................................................1-6
Chapter 2 BPDU Tunneling Configuration.................................................................................. 2-1
2.1 Introduction to BPDU Tunneling........................................................................................2-1
2.1.1 Why BPDU Tunneling.............................................................................................2-1
2.1.2 How BPDU Tunneling Works..................................................................................2-1
2.2 Configuring BPDU Isolation...............................................................................................2-3
2.3 Configuring BPDU Transparent Transmission ..................................................................2-3
2.4 Configuring Destination Multicast MAC Address for BPDU Tunnel Frames.....................2-4
2.5 BPDU Tunneling Configuration Example ..........................................................................2-5

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Chapter 1 QinQ Configuration
When configuring QinQ, go to these sections for information you are interested in:
zIntroduction to QinQ
zConfiguring Basic QinQ
zConfiguring Selective QinQ
zConfiguring the TPID Value to Be Carried in VLAN Tags
zQinQ Configuration Example
1.1 Introduction to QinQ
In the VLAN tag field defined in IEEE 802.1Q, only 12 bits are used for VLAN IDs, so a
switch can support a maximum of 4,094 VLANs. In actual applications, however, a
large number of VLANs are required to isolate users, especially in metropolitan area
networks (MANs), and 4,094 VLANs are far from satisfying such requirements.
1.1.1 Understanding QinQ
The port QinQ feature is a flexible, easy-to-implement Layer 2 VPN technique, which
enables the access point to encapsulate an outer VLAN tag in Ethernet frames from
customer networks (private networks), so that the Ethernet frameswill travel across the
service provider’s backbone network (public network) with double VLAN tags. The
inner VLAN tag is the customer network VLAN tag while the outer one is the VLAN tag
assigned by the service provider to the customer. In the public network, frames are
forwarded based on the outer VLAN tag only, with the source MAC address learned as
a MAC address table entry for the VLAN indicated by the outer tag, while the customer
network VLAN tag is transmitted as part of the data in the frames.
Figure 1-1 shows the structure of 802.1Q-tagged and double-tagged Ethernet frames.
The QinQ feature enables a device to support up to 4,094 x 4,094 VLANs to satisfy the
requirement for the amount of VLANs in the MAN.
Figure 1-1 Single-tagged frame structure vs. double-tagged Ethernet frame structure

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Advantages of QinQ:
zAddresses the shortage of public VLAN ID resource.
zEnables customers to plan their own VLAN IDs, without running into conflicts with
public network VLAN IDs.
zProvides an easy-to-do Layer 2 VPN solution for small-sized MANs or intranets.
Note:
The QinQ feature requires configurations only on the service provider network, and not
on the customer network.
1.1.2 Implementations of QinQ
There are two types of QinQ implementations: basic QinQ and selective QinQ.
1) Basic QinQ
Basic QinQ is a port-based feature, which is implemented through VLAN VPN.
With the VLAN VPN feature enabled on a port, when a frame arrives at the port, the
switch will tag it with the port’s default VLAN tag, regardless of whether the frame is
tagged or untagged. If the received frame is already tagged, this frame becomes a
double-tagged frame; if it is an untagged frame, it is tagged with the port’s default VLAN
tag.
2) Selective QinQ
Selective QinQ is a more flexible, VLAN-based implementation of QinQ. In addition to
all the functions of basic QinQ, selective QinQ can tag the frame with different outer
VLAN tags based on different inner VLAN IDs.
Note:
For an S5500-SI switch with both basic QinQ function and selective QinQ function
enabled, packets received are processed according to the settings of selective QinQ
first. Those that do not match selective QinQ settings are tagged with outer VLAN tags
according to the basic QinQ settings.
1.1.3 Modification of TPID Value of QinQ Frames
A VLAN tag uses the tag protocol identifier (TPID) field to identify the protocol type of
the tag. The value of this field, as defined in IEEE 802.1Q, is 0x8100.

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Figure 1-2 shows the 802.1Q-defined tag structure of an Ethernet frame.
Figure 1-2 VLAN Tag structure of an Ethernet frame
On devices of different vendors, the TPID field of the outer VLAN tag of QinQ frames
may have different default values. You can set and/or modify this TPID value.
Normally, a frame with the TPID field being 0x8100 is regarded carrying a VLAN tag
with it and is processed in the preset way when it reaches a switch. Those with their
TPID not being 0x8100 are regarded carrying no VLAN tag.
After you configure the TPID value to be adjustable, the switch replaces the TPID value
in the outer VLAN tag of a received frame with the customer-defined value before
forwarding the frame, so that the frame, when arriving at the public network, is of
specific protocol type. This enables a switch to communicate with devices of other
vendors.
The TPID in an Ethernet frame has the same position with the protocol type field in a
frame without a VLAN tag. To avoid problems in packet forwarding and handling in the
network, you cannot set the TPID value to any of the values in the table below.
Table 1-1 Reserved protocol type values
Protocol type Value
ARP 0x0806
PUP 0x0200
RARP 0x8035
IP 0x0800
IPv6 0x86DD
PPPoE 0x8863/0x8864
MPLS 0x8847/0x8848
IPX/SPX 0x8137
IS-IS 0x8000
LACP 0x8809
802.1x 0x888E

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Protocol type Value
Cluster 0x88A7
Reserved 0xFFFD/0xFFFE/0xFFFF
1.2 Configuring Basic QinQ
Follow these steps to configure basic QinQ:
To do... Use the command... Remarks
Enter system view system-view —
Enter
Ethernet
port view
interface
interface-type
interface-number
Enter
Ethernet
port view
or port
group
view
Enter port
group view
port-group {manual
port-group-name |
aggregation agg-id }
Required
Use either command.
Configurations made in
Ethernet port view will take
effect on the current port only;
configuration made in port
group view will takeeffect on all
ports in the port group.
Enable QinQ on the
port(s) qinq enable Required
Disabled by default.
1.3 Configuring Selective QinQ
The outer VLAN tag added to a frame by the basic QinQ feature is the VLAN tag
corresponding to the port’s default VLAN ID, while the selective QinQ feature allows
adding different outer VLAN tags based on different inner VLAN tags.
With selective QinQ configured on a port, the device attaches different outer VLAN tags
based on the inner VLAN tags; frames with a VLAN ID out of the range specified in the
raw-vlan-id inbound command are attached the port’s default VLAN tag as the outer
tag.
Follow these steps to configure selective QinQ:

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To do... Use the command... Remarks
Enter system view system-view —
Enter
Ethernet
port view
interface interface-type
interface-number
Enter
Ethernet port
view or port
group view Enter port
group view
port-group {manual
port-group-name |
aggregation agg-id }
Required
Use either command.
Configurations made in
Ethernet port view will
take effect on the current
port only; configurations
made in port group view
will take effect on all ports
in the port group.
Enter QinQ view and
configure the outer VLAN
tag for the port to add qinq vid vlan-id Required
Configure inner VLAN tags
corresponding to the outer
VLAN tags
raw-vlan-id inbound
{ all |vlan-id-list } Required
Caution:
zAn inner VLAN tag corresponds to only one outer VLAN tag. If you want to change
an outer VLAN tag, you must delete the old outer VLAN tag configuration and
configure a new outer VLAN tag.
zYou can configure selective QinQ and basic QinQ on the same port. The switch
uses the basic QinQ function to attach the port’s default VLAN tagas the outer tag to
frames that do not match the selective QinQ mapping rule.
1.4 Configuring the TPID Value to Be Carried in VLAN Tags
You can configure the TPID value to be carried in a VLAN tag TPID globally
(configuration will take effect on all ports of the device).
To do... Use the command... Remarks
Enter system view system-view —
Configure the TPID value to
be carried in VLAN tags qinq ethernet-type
hex-value
Optional
Both 0x8100 by default

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1.5 QinQ Configuration Example
I. Network requirements
zProvider A and Provider B are service provider network access devices.
zCustomer A, Customer B and Customer C are customer network access devices.
zProvider A and Provider B are interconnected through a configured trunk port.
Provider A belongs to VLAN 1000 of the service provider network, and Provider B
belongs to VLAN 2000 of the service provider network.
zThird-party devices are deployed between Provider A and Provider B, with a TPID
value of 0x8200.
After configuration, the network should satisfy the following requirement:
zFrames of VLAN 10 of Customer A and frames of VLAN 10 of Customer B can be
forwarded to each other through VLAN 1000 of the provider network;
zFrames of VLAN 20 of Customer A and frames of VLAN 20 of Customer C can be
forwarded to each other through VLAN 2000 of the provider network.
II. Network diagram
Public Network
VLAN1000,VLAN2000
TPID=0x8200
Customer A
Customer B Customer C
Provider A Provider B
GE1/0/1
Hybrid
GE1/0/2
Access
GE1/0/3
Trunk
GE1/0/1
Trunk GE1/0/2
Access
Figure 1-3 Network diagram for QinQ configuration

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III. Configuration procedure
Note:
With this configuration, the user must allow the QinQ packets to pass between the
devices of the service providers.
1) Configuration on Provider A
# Enter system view.
<ProviderA> system-view
zConfiguration on GigabitEthernet 1/0/1
# Configure GigabitEthernet 1/0/1 as a Hybrid port that permits frames of VLAN 1000
and VLAN 2000 to pass, and configure the port to remove the outer tag of the fames
when sending them out.
[ProviderA] interface GigabitEthernet 1/0/1
[ProviderA-GigabitEthernet1/0/1] port link-type hybrid
[ProviderA-GigabitEthernet1/0/1] port hybrid vlan 1000 2000 untagged
# Configure the port to tag frames from VLAN 10 with an outer tag with the VLAN ID of
1000.
[ProviderA-GigabitEthernet1/0/1] qinq vid 1000
[ProviderA-GigabitEthernet1/0/1-vid-1000] raw-vlan-id inbound 10
[ProviderA-GigabitEthernet1/0/1-vid-1000] quit
# Configure the port to tag frames from VLAN 20 with an outer tag with the VLAN ID of
2000.
[ProviderA-GigabitEthernet1/0/1] qinq vid 2000
[ProviderA-GigabitEthernet1/0/1-vid-2000] raw-vlan-id inbound 20
[ProviderA-GigabitEthernet1/0/1-vid-2000] quit
[ProviderA-GigabitEthernet1/0/1] quit
zConfiguration on GigabitEthernet 1/0/2
# Configure VLAN 1000 as the default VLAN of the port.
[ProviderA] interface GigabitEthernet 1/0/2
[ProviderA-GigabitEthernet1/0/2] port access vlan 1000
# Enable basic QinQ so that the port tags frames from VLAN 10 with an outer tag with
the VLAN ID of 1000.
[ProviderA-GigabitEthernet1/0/2] qinq enable
[ProviderA-GigabitEthernet1/0/2] quit
zConfiguration on GigabitEthernet 1/0/3.

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# Configure GigabitEthernet 1/0/3 as a trunk port, and permit frames of VLAN 1000 and
VLAN 2000 to pass.
[ProviderA] interface GigabitEthernet 1/0/3
[ProviderA-GigabitEthernet1/0/3] port link-type trunk
[ProviderA-GigabitEthernet1/0/3] port trunk permit vlan 1000 2000
# To enable interoperability with the third-party devices in the public network, set the
TPID value to be carried in VLAN Tags to 0x8200.
[ProviderA-GigabitEthernet1/0/3] quit
[ProviderA] qinq ethernet-type 8200
2) Configuration on Provider B
zConfiguration on GigabitEthernet 1/0/1
# Configure GigabitEthernet 1/0/1 as a trunk port, and permit frames of VLAN 1000 and
VLAN 2000.
<ProviderB> system-view
[ProviderB] interface GigabitEthernet 1/0/1
[ProviderB-GigabitEthernet1/0/1] port link-type trunk
[ProviderB-GigabitEthernet1/0/1] port trunk permit vlan 1000 2000
# To enable interoperability with the third-party devices in the public network, set the
TPID value to be carried in VLAN Tags to 0x8200.
[ProviderB-GigabitEthernet1/0/1] quit
[ProviderB] qinq ethernet-type 8200
zConfiguration on GigabitEthernet 1/0/2
# Configure VLAN 2000 as the default VLAN of the port.
[ProviderB] interface GigabitEthernet 1/0/2
[ProviderB-GigabitEthernet1/0/2] port access vlan 2000
# Enable basic QinQ so as to tag frames from VLAN 20 with an outer tag with the VLAN
ID of 2000.
[ProviderB-GigabitEthernet1/0/2] qinq enable
3) Configuration on devices on the public network
As third-party devices are deployed between Provider A and Provider B, what we
discuss here is only the basic configuration that should be made on the devices.
Configure that device connecting with GigabitEthernet 1/0/3 of Provider A and the
device connecting with GigabitEthernet 1/0/1 of Provider B so that their corresponding
ports send tagged frames of VLAN 1000 and VLAN 2000. The configuration steps are
omitted here.

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Chapter 2 BPDU Tunneling Configuration
When configuring BPDU tunneling, go to these sections for information you are
interested in:
zIntroduction to BPDU Tunneling
zConfiguring BPDU Isolation
zConfiguring BPDU Transparent Transmission
zConfiguring Destination Multicast MAC Address for BPDU Tunnel Frames
zBPDU Tunneling Configuration Example
2.1 Introduction to BPDU Tunneling
2.1.1 Why BPDU Tunneling
To avoid loops in your network, you can enable the spanning tree protocol (STP) on
your device. However, STP gets aware of the topological structure of a network by
means of bridge protocol data units (BPDUs) exchanged between different devices and
the BPDUs are Layer 2 multicast packets, which can be received and processed by all
STP-enabled devices on the network. This prevents each network from correctly
calculating its spanning tree. As a result, when redundant links exist in a network, data
loops will unavoidably occur.
By allowing each network to have its own spanning tree while running STP, BPDU
tunneling can resolve this problem.
zBPDU tunneling can isolate BPDUs of different customer networks, so that one
network is not affected by others while calculating the topological structure.
zBPDU tunneling enables BPDUs of the same customer network to be broadcast in
a specific VLAN in the provider network, so that the geographically dispersed
customer networks of the same customer can implement consistent spanning tree
calculation across the provider network.
2.1.2 How BPDU Tunneling Works
The BPDU tunneling implements the following two functions:
zBPDU isolation
zBPDU transparent transmission
The work process of IGMP is as follows:
I. BPDU isolation
When a port receives BPDUs of other networks, the port will discard the BPDUs, so that
they will not take part in spanning tree calculation. Refer to Configuring BPDU Isolation.

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II. BPDU transparent transmission
As shown in Figure 2-1, the upper part is the service provider network, and the lower
part represents the customer networks. The customer networks include network Aand
network B. Enabling the BPDU tunneling function on the BPDU input/output devices
across the service provider network allows BPDUs of the customer networks to be
transparently transmitted in the service provider network, and allows each customer
network to implement independent spanning tree calculation, without affecting each
other. Refer to Configuring BPDU Transparent Transmission.
Network
Network A Network B
Customer
networks
BPDU input/output
device BPDU input/output
device
Service provider
network
Figure 2-1 Network hierarchy of BPDU tunneling
zAt the BPDU input side, the device changes the destination MAC address of a
BPDU from a customer network from 0x0180-C200-0000 to a special multicast
MAC address, 0x010F-E200-0003 by default. In the service provider’s network,
the modified BPDUs are forwarded as data packets in the user VLAN.
zAt the packet output side, the device recognizes the BPDU with the destination
MAC address of 0x010F-E200-0003 and restores its original destination MAC
address 0x0180-C200-0000. Then, the device removes the outer tag, and sends
the BPDU to the destination customer network.
Note:
Make sure, through configuration, that the VLAN tag of the BPDU is neither changed
nor removed during its transparent transmission in the service provider network;
otherwise, the system will fail to transparently transmit the customer network BPDU
correctly.

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2.2 Configuring BPDU Isolation
Perform the following tasks to configure BPDU isolation:
To do... Use the command... Remarks
Enter system view system-view —
Enable BPDU tunneling
globally bpdu-tunnel dot1q
enable
Optional
Enabled by default
Enter Ethernet
port view interface interface-type
interface-number
Enter
Ethernet
port view
or port
group
view
Enter port
group view
port-group {manual
port-group-name |
aggregation agg-id }
Required
Use either command.
Configurations made in
Ethernet port view will
take effect on the
current port only;
configurations made in
port group view will take
effect on all ports in the
port group.
Enable BPDU tunneling for
the port(s) bpdu-tunnel dot1q
enable
Required
Disabled by default
Note:
zBPDU tunneling must be enabled globally before the BPDU tunnel configuration for
a port can take effect.
zThe BPDU tunneling feature is incompatible with the GVRP feature, so these two
features cannot be enabled at the same time. For introduction to GVRP, refer to
VLAN Configuration.
zThe BPDU tunneling feature is incompatible with the NTDP feature, so these two
features cannot be enabled at the same time. If you want to enable BPDU tunneling
on a port, use the undo ntdp enable command to disable NTDP first. For
introduction to NTDP, refer to Cluster Management Configuration.
2.3 Configuring BPDU Transparent Transmission
Perform the following tasks to configure BPDU transparent transmission:
To do... Use the command... Remarks
Enter system view system-view —
Enable BPDU tunneling
globally bpdu-tunnel dot1q
enable
Optional
Enabled by default

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To do... Use the command... Remarks
Enter Ethernet
port view interface interface-type
interface-number
Enter
Ethernet
port view
or port
group
view
Enter port
group view
port-group {manual
port-group-name |
aggregation agg-id }
Required
Use either command.
Configurations made in
Ethernet port view will
take effect on the
current port only;
configurations made in
port group view will take
effect on all ports in the
port group.
Enable BPDU tunneling on
the port(s) bpdu-tunnel dot1q
enable
Required
Disabled by default
Disable STP on the port(s) stp disable Required
Enabled by default
Enable BPDU tunneling for
STP on the port(s) bpdu-tunnel dot1q stp Required
Disabled by default
Note:
zBPDU tunneling must be enabled globally before the BPDU tunnel configuration for
a port can take effect.
zThe BPDU tunneling feature is incompatible with the GVRP feature, so these two
features cannot be enabled at the same time. For introduction to GVRP, refer to
VLAN Configuration.
zThe BPDU tunneling feature is incompatible with the NTDP feature, so these two
features cannot be enabled at the same time. If you want to enable BPDU tunneling
on a port, use the undo ntdp enable command to disable NTDP first. For
introduction to NTDP, refer to Cluster Management Configuration.
2.4 Configuring Destination Multicast MAC Address for
BPDU Tunnel Frames
By default, the destination multicast MAC address for BPDU Tunnel frames is
0x010F-E200-0003. You can modify it to 0x0100-0CCD-CDD0, 0x0100-0CCD-CDD1
or 0x0100-0CCD-CDD2 through the following configuration.
Follow these steps to configure destination multicast MAC address for BPDU tunnel
frames:

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To do… Use the command… Remarks
Enter system view system-view —
Configure the
destination multicast
MAC address for BPDU
Tunnel frames
bpdu-tunnel tunnel-dmac
mac-address
Optional
0x010F-E200-0003 by
default.
2.5 BPDU Tunneling Configuration Example
I. Network requirements
zCustomer A, Customer B, Customer C, and Customer D are customer network
access devices.
zProvider A, Provider B, and Provider C are service provider network access
devices, which are interconnected through configured trunk ports.
The configuration is required to satisfy the following requirements:
zGeographically dispersed customer network devices Customer A, Customer C
and Customer D can implement consistent spanning tree calculation across the
service provider network.
zBPDU packets from Customer B are isolated so it does not take part in the
spanning tree calculation.
II. Network diagram
Figure 2-2 Network diagram for BPDU tunneling configuration
III. Configuration procedure
1) Configuration on Provider A

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# Configure BPDU transparent transmission on GigabitEthernet 1/0/1.
<ProviderA> system-view
[ProviderA] interface GigabitEthernet 1/0/1
[ProviderA-GigabitEthernet1/0/1] port access vlan 2
[ProviderA-GigabitEthernet1/0/1] stp disable
[ProviderA-GigabitEthernet1/0/1] undo ntdp enable
[ProviderA-GigabitEthernet1/0/1] bpdu-tunnel dot1q enable
[ProviderA-GigabitEthernet1/0/1] bpdu-tunnel dot1q stp
2) Configuration on Provider B
# Configure BPDU isolation on GigabitEthernet 1/0/2.
<ProviderB> system-view
[ProviderB] interface GigabitEthernet 1/0/2
[ProviderB-GigabitEthernet1/0/2] port access vlan 4
[ProviderB-GigabitEthernet1/0/2] undo ntdp enable
[ProviderB-GigabitEthernet1/0/2] bpdu-tunnel dot1q enable
3) Configuration on Provider C
# Configure BPDU transparent transmission on GigabitEthernet 1/0/3.
<ProviderC> system-view
[ProviderC] interface GigabitEthernet 1/0/3
[ProviderC-GigabitEthernet1/0/3] port access vlan 2
[ProviderC-GigabitEthernet1/0/3] stp disable
[ProviderC-GigabitEthernet1/0/3] undo ntdp enable
[ProviderC-GigabitEthernet1/0/3] bpdu-tunnel dot1q enable
[ProviderC-GigabitEthernet1/0/3] bpdu-tunnel dot1q stp
# Configure BPDU transparent transmission on GigabitEthernet 1/0/4.
[ProviderC-GigabitEthernet1/0/3] quit
[ProviderC] interface GigabitEthernet 1/0/4
[ProviderC-GigabitEthernet1/0/4] port access vlan 2
[ProviderC-GigabitEthernet1/0/4] stp disable
[ProviderC-GigabitEthernet1/0/4] undo ntdp enable
[ProviderC-GigabitEthernet1/0/4] bpdu-tunnel dot1q enable
[ProviderC-GigabitEthernet1/0/4] bpdu-tunnel dot1q stp
Note:
When STP works stably on the customer network, if Customer A acts as theroot bridge,
the ports of Customer C and Customer D connected with Provider C can receive
BPDUs from Customer A. Since BPDU isolation is enabled on Customer B, the port
that connects Customer B to Provider B cannot receive BPDUs from Customer A.