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Cisco IP Solution Center L2VPN and Carrier Ethernet User Guide, 6.0
Appendix C Setting Up VLAN Translation
Platform-Specific Usage Notes
• The CE VLAN becomes available to be translated again.
• The “translated to” PE VLAN is released.
• If the link being deleted is the last “CE-PE” pair on this UNI port, and there is no EWS (EPL) service
on this port, then this port is set to new. In addition, the outer VLAN is released.
Platform-Specific Usage Notes
VLAN translation is available on 7600 and 3750 ME platforms. The 7600 and 3750 ME have different
ways to support VLAN translation. Not only is the command syntax different, but so is the place where
the VLAN translation is carried out. On the 7600, for 1:1 VLAN translation, the operation is done on the
PFC card. For 2:1 VLAN translation, the operation is done on the uplink GE-WAN (OSM module). On
the 3750 ME, however, both translations occur on the uplinks (ES ports).
VLAN Translation on the 3750
Be aware of the following points when performing VLAN translation on the 3750.
• The 3750 where VLAN translation occurs should be designated as a U-PE or PE-AGG role, not
• VLAN translation on the up link (ES) port should be performed on the Gigabit 1/1/1 or Gigabit 1/1/2
• If a 1:1 VLAN translation occurs on a ring that is made of 3750 PEs, all the 3750s use the ES port
as uplink ports (the “east” and “west” ports) to connect other ring nodes.
VLAN Translation on the 7600
Be aware of the following points when performing VLAN translation on the 7600.
• 1:1 VLAN translation always occurs on the UNI port. However, not every Ethernet interface will
support 1:1 VLAN translation. Such support is dependent on the line card.
• 2:1 VLAN translation always occurs on the GE-WAN port. The port must be an NNI uplink port.
• 2:1 VLAN translation only occurs on a 7600 that is a U-PE or a PE-AGG, not an N-PE. The reason
is when the 2:1 VLAN translation is performed on the GE-WAN interface, this interface can no
longer perform L3VPN and L2VPN service using the translated new VLAN. The L3/L2VPN service
has to be provisioned on another (N-PE) box.
Failed Service Requests When Hardware Does Not Support VLAN Translation
For the 1:1 VLAN translation feature, a service request goes to the Fail Deployed state if the target
hardware (line card) does not support the VLAN translation. The reason the service request goes to the
Fail Deployed state instead of Invalid is that ISC does not know beforehand whether a particular line
card will accept or reject the VLAN translation CLI commands. In this case, ISC attempts to push down
the commands and the deployment fails. An Invalid status means ISC detects something wrong (in
advance) and aborts the provisioning task. No CLI is pushed down in that case. This is a general behavior
of ISC when a given hardware does not support a feature. In these cases, it is the user’s responsibility to
select proper hardware to support the intended service.