Juniper Networks JUNOS OS 10.4 User Manual

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If VLANs 1 through 1000 for customer C1 span the same sites, then the

vlan-id all

and

vlan-range

statements provide a way to switch all of these VLANs with a minimum

configuration effort and fewer switch resources.

NOTE:

You cannot use the

vlan-id all

statement if you configure an IRB

interface on one or more of the VLANs.

Alternatively, instead of configuring a VPLS instance, you can define a virtual switch with
a bridge domain and associate the logical interfaces as trunk ports with the bridge domain.
This configuration is necessary if you want to configure a list or range of VLAN IDs on the
logical interfaces and use the

vlan-id all

statement to normalize VLANs.

A Layer 2 virtual switch, which isolates a LAN segment with its spanning-tree protocol
instance and separates its VLAN ID space, filters and forwards traffic only at the data
link layer. Each bridge domain consists of a set of logical ports that participate in Layer
2 learning and forwarding.

You can configure VPLS ports in a virtual switch so that the logical interfaces of the Layer
2 bridge domains in the virtual switch can handle VPLS routing instance traffic. VPLS
configuration no longer requires a dedicated routing instance of type vpls. Packets received
on a Layer 2 trunk interface are forwarded within a bridge domain that has the same
VLAN identifier. A trunk interface is implicitly associated with bridge domains based on
VLAN membership.

You can use either of the following two mechanisms to normalize VLAN identifiers and
process them in a bridge domain or a VPLS routing instance:

•

By using the

input-vlan-map

and the

output-vlan-map

statements at the

[edit interfaces

interface-name]

hierarchy level to configure VLAN mapping.

•

By using either the

vlan-id

statement or the

vlan-tags

statement to configure a

normalizing VLAN identifier.

The

vlan-id

and

vlan-tags

statements are used to specify the normalizing VLAN identifier

under the bridge domain or VPLS routing instance. The normalizing VLAN identifier is
used to perform the following functions:

•

Translate, or normalize, the VLAN tags of received packets received into a learn VLAN
identifier.

•

• Create multiple learning domains that each contain a learn VLAN identifier. A learning
domain is a MAC address database to which MAC addresses are added based on the
learn VLAN identifier.

If you configure the

vlan-id all

statement in a VPLS routing instance, we recommend

using the

input-vlan-map pop

and

output-vlan-map push

statements on the logical

interface to pop the service VLAN ID on input and push the service VLAN ID on output
and in this way limit the impact of doubly-tagged frames on scaling. You cannot use the
native

vlan- id

statement when the

vlan-id all

statement is included in the configuration.

Chapter 4: VLANs Within Bridge Domain and VPLS Environments