The Carrier Ethernet Model
Egress Behavior
The EFP matching criteria can also be used on egress to police the frames that can egress from the EFP, based
on the platform support. Frames that do not match the criteria (source/destination MAC match criteria are
reversed) are dropped.
Applying Features
After the frames are matched to a particular EFP, any appropriate features can be applied. In this context,
"features" means any frame manipulations specified by the configuration as well as things such as QoS and
ACLs. The Ethernet infrastructure provides an appropriate interface to allow the feature owners to apply their
features to an EFP. Hence, IM interface handles are used to represent EFPs, allowing feature owners to manage
their features on EFPs in the same way the features are managed on regular interfaces or subinterfaces.
The only L2 features that can be applied on an EFP that is part of the Ethernet infrastructure are the L2 header
encapsulation modifications. The L2 features are described in this section.
Encapsulation Modifications
EFP supports these L2 header encapsulation modifications on both ingress and egress:
• Push 1 or 2 VLAN tags
• Pop 1 or 2 VLAN tags
Note
This modification can only pop tags that are matched as part of the EFP.
• Rewrite 1 or 2 VLAN tags:
• The VLAN tag type, that is, C-VLAN, S-VLAN, or I-TAG. The ethertype of the 802.1Q C-VLAN tag
• The VLAN ID. 0 can be specified for an outer VLAN tag to generate a priority-tagged frame.
Note
For tag rewrites, the CoS bits from the previous tag should be preserved in the same way as the DEI bit for
802.1ad encapsulated frames.
Defining Data-Forwarding Behavior
The EFP can be used to designate the frames belonging to a particular Ethernet flow forwarded in the data
path. These forwarding cases are supported for EFPs in Cisco IOS XR software:
• Rewrite outer tag
• Rewrite outer 2 tags
• Rewrite outer tag and push an additional tag
• Remove outer tag and rewrite inner tag
For each of the VLAN ID manipulations, these can be specified:
is defined by the dot1q tunneling type command.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
Applying Features
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