Examples: Configuring S-Vlan Subinterface With An Untagged C-Vlan Id - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - BGP AND MPLS CONFIGURATION GUIDE 2010-10-12 Configuration Manual

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Examples: Configuring S-VLAN Subinterface with an Untagged C-VLAN ID

Copyright © 2010, Juniper Networks, Inc.
is sent to the subinterface on the egress line module, point D, for further processing. At
point D, for ES2 4G LMs, the packet is sent to the remote CE-facing device, depending
on the configuration of the S-VLAN subinterface. If the packet arrives with a single or no
tag, the router adds the S-VLAN tag and sends it to the CE-facing device. On ES2 10G
LMs, ES2 10G Uplink LMs, and ES2 10G ADV LMs, at point D, the packet is forwarded to
the CE-facing device without any modification.
In the same scenario, when Ethernet raw mode is enabled on the S-VLAN subinterface
of the PE devices, the processing of Ethernet packets is performed in a slightly different
way. At the S-VLAN subinterface on an ingress ES2 4G LM, ES2 10G LM, ES2 10G Uplink
LM, and ES2 10G ADV LM, point A, inside PE1, the S-VLAN tag is removed from the received
packet before being forwarded to the subinterface on the egress line module, B, inside
PE1. At point B, the MPLS encapsulation header is added to the packet and the egress
line module forwards it to the MPLS network. This functionality is the same for both ES2
4G LMs ,ES2 10G LMs, ES2 10G Uplink LMs, and ES2 10G ADV LMs. When the packet
reaches the subinterface on the ingress ES2 4G LMs, ES2 10G LMs, ES2 10G Uplink LMs,
and ES2 10G ADV LMs, point C, inside PE2, the added MPLS header is removed and the
packet is sent to the subinterface on the egress line module, point D, for further processing.
This behavior is the same, regardless of whether raw mode encapsulation is enabled or
not. At point D, for both ES2 4G LMs, ES2 10G LMs, ES2 10G Uplink LMs, and ES2 10G
ADV LMs, the S-VLAN tag is inserted into the packet and sent to the CE-facing device at
the remote site.
route interface
mpls-relay
Ethernet Raw Mode Encapsulation for Martini Layer 2 Transport Overview on page 526
Consider the following example in which an S-VLAN interface is configured with an
S-VLAN ID of 4 and the C-VLAN tag as any. Only packets that are double tagged, which
contain both the S-VLAN and C-VLAN tags, are matched for this S-VLAN subinterface.
Packets that are only S-VLAN tagged and do not contain a C-VLAN tag are not matched
for the S-VLAN subinterface.
host1(config)#interface fastEthernet 2/0
host1(config-if)#encapsulation vlan
host1(config-if)#interface fastEthernet 2/0.1
host1(config-if)#svlan id 4 any
host1(config-if)#svlan ethertype 8100
The following are the limitations in this setup when the user at the CE-side tags all the
packets from the CE-side, including C-VLAN tagged or untagged packets, with an S-VLAN
ID to identify a particular user:
If the S-VLAN Ethertype is 0x8100, then you must create two sub-interfaces, one for
the double-tagged packets, and the other for single-tagged packets to process both
these types of packets.
Chapter 9: Configuring Layer 2 Services over MPLS
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