Related Topics route interface•
• mpls-relay
• Ethernet Raw Mode Encapsulation for Martini Layer 2 Transport Overview on page 522
Examples: Configuring S-VLAN Subinterface with an Untagged C-VLAN ID
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.
•
If the S-VLAN Ethertype is a value other than 0x8100, S-VLAN-tagged packets without
a C-VLAN ID cannot even be processed.
To enable Ethernet raw mode encapsulation and to enable the S-VLAN subinterface to
remove or add the S-VLAN tag at the PE-facing routers in the first scenario, two
pseudowires need to be created. Figure 126 on page 557 illustrates such a scenario in which
a sending CE device and a receiving CE device are connected using PE routers through a
MPLS network.
Figure 126: Martini Circuit with Two Pseudowires Between PE-Facing Routers
PE1CE1 CE2PE2
MPLS network
X tagged
for traffic
from CPE2
g016508
Ethernet traffic
with or without
SVLAN tag,
based on
subinterface
configuration
PW1 for double-tagged traffic
Pseudowire
PW2 for single-tagged traffic
X:Y tagged
for traffic
from CPE1
CPE1
CPE2
CVLAN Y
Untagged
557Copyright © 2010, Juniper Networks, Inc.
Chapter 9: Configuring Layer 2 Services over MPLS
To Next Page
Loading...
Need help?
General
