Vlan And S-Vlan Platform Considerations; Module Requirements - Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual

VLAN and S-VLAN Platform Considerations

Module Requirements

Copyright © 2010, Juniper Networks, Inc.
frames enables the construction of a maximum of 4096 distinct VLANs. In an Ethernet
B-RAS application environment, however, this VLAN limit is inadequate. A stacked VLAN
(S-VLAN) provides a two-level VLAN tag structure, which extends the VLAN ID space to
more than 16 million VLANs.
Creating an S-VLAN requires the use of a second encapsulation tag. The router performs
decapsulation twice, once to get the S-VLAN tag and once to get the VLAN tag. This
double tagging approach enables more than 16 million address possibilities, which more
than satisfies the scaling requirement for Ethernet B-RAS applications.
VLAN and S-VLAN subinterfaces can coexist over the same VLAN major interface. You
configure S-VLANs in the same way that you configure VLANs, with the addition of certain
commands.
NOTE: See JunosE Release Notes, Appendix A, System Maximums for S-VLAN limitations.
Like VLANs, all S-VLAN subinterfaces use the MAC address of the Ethernet interface
over which they are configured. For more information about assigning unique MAC address
to the S-VLAN subinterface when assigning VLAN or S-VLAN IDs, see "VLAN Overview"
on page 167.
You can configure VLAN and S-VLAN subinterfaces on the following E Series Broadband
Services Routers:
E120 router
E320 router
ERX1440 router
ERX1410 router
ERX710 router
ERX705 router
ERX310 router
For information about the modules supported on E Series routers:
See the ERX Module Guide for modules supported on ERX7xx models, ERX14xx models,
and the ERX310 router.
See the E120 and E320 Module Guide for modules supported on the E120 and E320
routers.
Chapter 5: Configuring VLAN and S-VLAN Subinterfaces
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