Cisco A9K-SIP-700 Configuration Guidelines

• A flooded copy of the frame is sent to GigabitEthernet subinterface 0/1/0/3.1.
• GigabitEthernet subinterface 0/1/0/3.1 adds a second tag.
• The frame receives an L2PT encapsulation by GigabitEthernet subinterface 0/1/0/3.1 before it leaves
router R1 through the GigabitEthernet interface 0/1/0/3.
The frame is now double-tagged (100 inner, 500 outer) and has the L2PT MAC
DA.
Note
• The frame passes to router R2 GigabitEthernet interface 0/5/0/4 because of the L2PT encapsulation.
• The frame after having entered router R2 on GigabitEthernet interface 0/5/0/4 is directed to GigabitEthernet
subinterface 0/5/0/4.1.
• On entering GigabitEthernet subinterface 0/5/0/4.1, an L2PT decapsulation operation is performed on
the frame.
• The outer tag ID 500 is removed by GigabitEthernet subinterface 0/5/0/4.1
• Router R2’s bridge (r2-bridge) floods the frames to all ACs.
• Ethernet egress filtering drops the frames on all ACs except the AC through which the frame exits.
• As the frame exits router R2 from GigabitEthernet subinterface 0/5/0/5.1, the tag of ID 100 is removed.
• The frame that exits router R2 from GigabitEthernet interface 0/5/0/5 is identical to the original frame
that entered router R1 through GigabitEthernet interface 0/1/0/1.
L2PT Configuration Notes
Keep these points in mind while configuring L2PT:
• The l2protocol command can be configured on either a main or L2 subinterface.
• The l2protocol command can be configured on physical or bundle interfaces.
• When the l2protocol and ethernet filtering commands are configured on the same interface, L2PT
encapsulation occurs before ethernet filtering. This means that L2PT prevents the CDP, STP, and VTP
protocol frames from being dropped by ethernet filtering.
• When L2PT is configured with other interface features, L2PT encapsulation occurs before the processing
for other interface features.
• L2PT encapsulation and decapsulation is supported for untagged protocol frames, single-tagged, and
double-tagged frames. Tag Ethertypes of 0x8100, 0x88A8, and 0x9100 are supported, however, 0x9200
is not.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
45
Ethernet Features
L2PT Configuration Notes

Cisco A9K-SIP-700 Specifications

General

Brand	Cisco
Model	A9K-SIP-700
Category	Network Router
Language	English