Juniper Networks JUNOS OS 10.4 - Manual (Page 64)

• Example: Configuring a Provider Bridge Network with Normalized VLAN Tags on page 47
• Example: Configuring a Provider VPLS Network with Normalized VLAN Tags on page 51
• Example: Configuring One VPLS Instance for Several VLANs on page 55
Packet Flow Through a Bridged Network with Normalized VLANs
Packets received over a Layer 2 logical interface for bridging are processed in a strict
sequence of steps.
Packets received over a Layer 2 logical interface for bridging when a normalized VLAN is
configured with a single or inner and outer VLAN identifier tags under the bridge domain
or the VPLS routing instance are processed with the following steps:
1. A packet received on a physical port is only accepted for further processing if the VLAN
tags of the received packet match the VLAN tags associated with one of the logical
interfaces configured on that physical port.
2. The VLAN tags of the received packet are compared with the normalized VLAN tags.
If the VLAN tags of the received packet are different from the normalized VLAN, then
the appropriate VLAN operations (such as push-push, pop-pop, pop-swap, swap-swap,
swap, and others) are done implicitly to convert the received VLAN tags to the
normalized VLAN tag value. For more information these operations, see the Junos
Routing Protocols Configuration Guide.
3. If the source MAC address of the received packet is not present in the source MAC
table, then it is learned based on the normalized VLAN tag value.
4. The packet is forwarded toward one or more egress Layer 2 logical interfaces based
on the destination MAC address. A packet with a known unicast destination MAC
address is only forwarded to one egress logical interface. For each egress Layer 2
logical interface, the normalized VLAN tag within the packet is compared with the
VLAN tags configured on that logical interface. If the VLAN tags associated with an
egress logical interface do not match the normalized VLAN tag in the frame, then
appropriate VLAN operations (such as push-push, pop-pop, pop-swap, swap-swap,
swap, and others) are implicitly done to convert the normalized VLAN tags to the
VLAN tags of the egress logical interface. For more information these operations, see
the Junos Routing Protocols Configuration Guide.
Related
Documentation
Ethernet Networking •
• VLANs Within a Bridge Domain or VPLS Instance on page 43
• Configuring a Normalized VLAN for Translation or Tagging on page 45
• Configuring Learning Domains for VLAN IDs Bound to Logical Interfaces on page 47
• Example: Configuring a Provider Bridge Network with Normalized VLAN Tags on page 47
• Example: Configuring a Provider VPLS Network with Normalized VLAN Tags on page 51
• Example: Configuring One VPLS Instance for Several VLANs on page 55
Copyright © 2013, Juniper Networks, Inc. 44
Junos OS 13.1 MX Series 3D Universal Edge Routers Solutions Guide