Configuring IEEE 802.1Q Tunneling
11-13
11
VLAN IDs to each customer would restrict customer configurations, require intensive
processing of VLAN mapping tables, and could easily exceed the maximum VLAN
limit of 4096.
QinQ tunneling uses a single Service Provider VLAN (SPVLAN) for customers who
have multiple VLANs. Customer VLAN IDs are preserved and traffic from different
customers is segregated within the service provider’s network even when they use
the same customer-specific VLAN IDs. QinQ tunneling expands VLAN space by
using a VLAN-in-VLAN hierarchy, preserving the customer’s original tagged packets,
and adding SPVLAN tags to each frame (also called double tagging).
A port configured to support QinQ tunneling must be set to tunnel port mode. The
Service Provider VLAN (SPVLAN) ID for the specific customer must be assigned to
the QinQ tunnel access port on the edge switch where the customer traffic enters
the service provider’s network. Each customer requires a separate SPVLAN, but this
VLAN supports all of the customer's internal VLANs. The QinQ tunnel uplink port
that passes traffic from the edge switch into the service provider’s metro network
must also be added to this SPVLAN. The uplink port can be added to multiple
SPVLANs to carry inbound traffic for different customers onto the service provider’s
network.
When a double-tagged packet enters another trunk port in an intermediate or core
switch in the service provider’s network, the outer tag is stripped for packet
processing. When the packet exits another trunk port on the same core switch, the
same SPVLAN tag is again added to the packet.
When a packet enters the trunk port on the service provider’s egress switch, the
outer tag is again stripped for packet processing. However, the SPVLAN tag is not
added when it is sent out the tunnel access port on the edge switch into the
customer’s network. The packet is sent as a normal IEEE 802.1Q-tagged frame,
preserving the original VLAN numbers used in the customer’s network.
Layer 2 Flow for Packets Coming into a Tunnel Access Port
Tunnel Uplink Ports
Double-Tagged Packets
Outer Tag - Service Provider VID
Inner Tag - Customer VID
QinQ Tunneling
Service Provider
(edge switch A)
Customer A
(VLANs 1-10)
Customer B
(VLANs 1-50)
Customer A
(VLANs 1-10)
Customer B
(VLANs 1-50)
Service Provider
(edge switch B)
VLAN 10
Tunnel
Port
Access
Tunnel
Port
VLAN 20
Access
VLAN 10
Tunnel
Port
Access
Tunnel
Port
VLAN 20
Access
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......