Specifications

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Cisco SCE 2000 and SCE 1000 CLI Command Reference
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Chapter 2 CLI Command Reference
asymmetric-L2-support
asymmetric-L2-support
Configures the system to treat flows as having asymmetric layer 2 characteristics (including Ethernet,
VLAN, MPLS, and L2TP), for the purpose of packet injection.
Use the no form of the command to disable asymmetric L2 support.
asymmetric-L2-support
no asymmetric-L2-support
Syntax Description This command has no arguments or keywords.
Command Default By default, asymmetric layer 2 support is disabled.
Command Modes Interface Linecard Configuration
Command History This table includes the following release-specific history entries:
Usage Guidelines You should enable asymmetric layer 2 support in cases where the following conditions apply for any
flows:
• Each direction of the flow has a different pair of MAC addresses
• The routers do not accept packets with the MAC address of the other link
Note 'Asymmetric routing topology' support and 'asymmetric tunneling support' are two separate features.
Asymmetric routing topology refers to topologies where the SCE platform might see some flows only
in one direction (upstream/downstream). Asymmetric tunneling support (asymmetric L2 support) refers
to the ability to support topologies where the SCE platform sees both directions of all flows, but some
of the flows may have different layer 2 characteristics (like MAC addresses, VLAN tags, MPLS labels
and L2TP headers), which the SCE platform must specifically take into account when injecting packets
into the traffic (such as in block and redirect operations). Note as well, that in order to support
asymmetric layer 2, the SCE platform switches to asymmetric flow open mode, which incurs a certain
performance penalty. This is NOT the case for asymmetric routing topology.
Authorization: admin
Release Modification
3.1.6 This command was introduced.