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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 11 Configuring Ethernet Virtual Connections (EVCs)
Configuring EFPs
If a packet with VLAN tag 10 or 20 is received on Gigabit Ethernet 0/3, the ingress logical port would
be service instance 3. For the frame to be forwarded on a service instance, the egress frame must match
the encapsulation defined on that service instance after the rewrite is done. Service instance 1 checks for
outermost VLAN 20; service instance 2 checks for VLAN 30. In this example, the frame with VLAN
tags 10 and 20 can be sent to service instance 1 but not to service instance 2.
Examples of Unsupported Configurations
Overlapping Encapsulation
The switch does not allow overlapping encapsulation. Overlapping encapsulation configuration occurs
when two EFPs are configured on the same port and the same bridge domain and the set of
encapsulations on one EFP is a subset of the encapsulations on the other EFP.
These are examples of overlapping encapsulation:
Example 1
Service instance 2 configuration is rejected because the service instance 1 encapsulation default is a
superset of service instance 2 encapsulation dot1q 10.
Switch (config)#
interface gigabitethernet 0/1
Switch (config-if)#
switchport mode trunk
Switch (config-if)#
switchport mode allowed vlan none
Switch (config-if)#
service instance
1
ethernet
Switch (config-if-srv)#
encapsulation default
Switch (config-if-srv)#
bridge-domain 10
Switch (config-if-srv)#
exit
Switch (config-if)#
service instance
2 ethernet
Switch (config-if-srv)#
encapsulation dot1q 10
Switch (config-if-srv)#
bridge-domain 10
Example 2
Service instance 2 configuration is rejected because service instance 1 encapsulation dot1q any is
superset of service instance 2 encapsulation dot1q 10.
Switch (config)#
interface gigabitethernet 0/1
Switch (config-if)#
switchport mode trunk
Switch (config-if)#
switchport mode allowed vlan none
Switch (config-if)#
service instance
1
ethernet
Switch (config-if-srv)#
encapsulation dot1q any
Switch (config-if-srv)#
bridge-domain 10
Switch (config-if-srv)#
exit
Switch (config-if)#
service instance
2 ethernet
Switch (config-if-srv)#
encapsulation dot1q 10
Switch (config-if-srv)#
bridge-domain 10
Example 3
Service instance 2 configuration is rejected. Both service instances have the same dot1q vlan 10
encapsulation, but matching cos 3 in service instance 1 is subset of service instance 2 cos match all (the
default when not specified). Matching etype ipv4 in service instance 2 is a subset of service instance 1
etype match all (the default when not specified).
Switch (config)#
interface gigabitethernet 0/1
Switch (config-if)#
switchport mode trunk
