Understanding VPLS Interfaces

Interface Name

Specify both the physical and logical portions of the interface name, in the following format:

physical.logical

For example, in ge-1/2/1.2, ge-1/0/1 is the physical portion of the interface name and 2 is the logical portion. If you do not specify the logical portion of the interface name, 0 is set by default. A logical interface can be associated with only one routing instance.

Encapsulation Type

The physical link-layer encapsulation type for a VPLS interface can be one of the following:

• ethernet-vpls—Use Ethernet VPLS encapsulation on Ethernet interfaces that have VPLS enabled and that must accept packets carrying standard Tag Protocol Identifier (TPID) values.
• extended-vlan-vpls—Use extended virtual LAN (VLAN) VPLS encapsulation on Ethernet interfaces that have VLAN 802.1Q tagging and VPLS enabled and that must accept packets carrying TPIDs 0x8100, 0x9100, and 0x9901. All VLAN IDs from 1 through 1023 are valid for VPLS VLANs on Fast Ethernet interfaces, and all VLAN IDs from 1 through 4094 are valid for VPLS VLANs on Gigabit Ethernet interfaces.
• vlan-vpls—Use VLAN VPLS encapsulation on Ethernet interfaces with VLAN tagging and VPLS enabled. Interfaces with VLAN VPLS encapsulation accept packets carrying standard TPID values only. You must configure this encapsulation type on both the physical interface and the logical interface. VLAN IDs 1 through 511 are reserved for normal Ethernet VLANs, IDs 512 through 1023 are reserved for VPLS VLANs on Fast Ethernet interfaces, and IDs 512 through 4094 are reserved for VPLS VLANs on Gigabit Ethernet interfaces.
• flexible-ethernet-services—Use flexible Ethernet services encapsulation when you want to configure multiple per-unit Ethernet encapsulations. This encapsulation type allows you to configure any combination of route, TCC, CCC, and VPLS encapsulations on a single physical port. Aggregated Ethernet bundles cannot use this encapsulation type.

  For flexible Ethernet services encapsulation, VLAN IDs from 1 through 511 are no longer reserved for normal VLANs.

Flexible VLAN Tagging

For untagged packets to be accepted on an 802.1Q VLAN-tagged port, specify the native VLAN ID with the flexible VLAN tagging option. (No other flexible VLAN tagging features are supported.)

VLAN Rewrite

You can rewrite VLAN tags on VPLS interfaces. Rewriting VLAN tags allows you to use an additional (outer) VLAN tag to differentiate between CE devices that share a VLAN ID.

You can configure rewrite operations to stack (push), remove (pop), or rewrite (swap) tags on single-tagged frames. If a port is not configured for VLAN tagging, rewrite operations are not supported on any logical interface on that port.

• pop—Remove a VLAN tag from the top of the VLAN tag stack. The outer VLAN tag of the frame is removed.
• push—Add a new VLAN tag to the top of the VLAN stack. An outer VLAN tag is pushed in front of the existing VLAN tag.
• swap—Replace the VLAN tag at the top of the VLAN tag stack with a user-specified VLAN tag value.

You perform VLAN rewrite operations by applying input and output VLAN maps at the ingress and egress, respectively, of the interface. For incoming frames, use the input-vlan-map; for outgoing frames, use the output-vlan-map.

The VPLS implementation on J Series or SRX Series devices does not support dual-tagged frames. Therefore, VLAN rewrite operations are not supported on dual-tagged frames. VLAN rewrite operations such as pop-pop, pop-swap, push-push, swap-push, and swap-swap, which are supported on M Series and T Series routing platforms, are not supported on J Series or SRX Series devices.