Configuring The Label Block Size For Vpls; Pe Router Mesh Groups For Vpls Routing Instances - Juniper EX9200 Features Manual

VPLS Feature Guide for EX9200 Switches

Configuring the Label Block Size for VPLS

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Documentation

PE Router Mesh Groups for VPLS Routing Instances

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VPLS MPLS packets have a two-label stack. The outer label is used for normal MPLS
forwarding in the service provider's network. If BGP is used to establish VPLS, the inner
label is allocated by a PE router as part of a label block. One inner label is needed for
each remote VPLS site. Four sizes are supported. We recommend using the default size
of 8, unless the network design requires a different size for optimal label usage, to allow
the router to support a larger number of VPLS instances.
NOTE: In the VPLS documentation, the word router in terms such as PE router
is used to refer to any device that provides routing functions.
If you allocate a large number of small label blocks to increase efficiency, you also increase
the number of routes in the VPLS domain. This has an impact on the control plane
overhead.
Changing the configured label block size causes all existing pseudowires to be deleted.
For example, if you configure the label block size to be 4 and then change the size to 8,
all existing label blocks of size 4 are deleted, which means that all existing pseudowires
are deleted. The new label block of size 8 is created, and new pseudowires are established.
Four label block sizes are supported: 2, 4, 8, and 16. Consider the following scenarios:
2—Allocate the label blocks in increments of 2. For a VPLS domain that has only two
sites with no future expansion plans.
4—Allocate the label blocks in increments of 4.
8 (default)—Allocate the label blocks in increments of 8.
16—Allocate the label blocks in increments of 16. A label block size of 16 enables you
to minimize the number of routes in the VPLS domain. Use this setting only if the number
of routes is the most important concern.
Configure the label block size:
[edit routing-instances instance-name protocols vpls]
user@router# set label-block-size
Configuring VPLS Routing Instances on page 21
A PE router mesh group consists of a set of routers participating in a VPLS routing instance
that share the same signaling protocol, either BGP or LDP. Each VPLS routing instance
can have just one BGP mesh group. However, you can configure multiple LDP mesh
groups for each routing instance.
The Junos OS can support up to 16 mesh groups on MX Series routers and up to 128 on
M Series and T Series routers. However, two mesh groups are created by default, one for
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