Cisco 3845 - Security Bundle Router Software Manual page 254

Configuring Other Features on EFPs
Figure 11-9
VLAN tag
On ingress at the switchport, a VLAN tag is popped at the switchport trunk, and an untagged packet is
bridged over bridge-domain 10. On egress at the EFP with no rewrite, there is an encapsulation mismatch
because the bridged packet is untagged, and the encapsulation is 802.1q VLAN 10. Therefore, the packet
is dropped.
Figure 11-10
Outer
VLAN tag
10
On ingress at the switchport, the outer most VLAN tag (VLAN 10) is popped at the switchport trunk and
singled-tagged packet (VLAN 20) is bridged over bridge-domain 10. On egress at the EFP with no
rewrite, the bridged packet tag (VLAN 20) matches the encapsulation, and a single-tagged packet
(VLAN 20) is sent out on the EFP.
On ingress at the EFP with no rewrite, a single- tagged packet (VLAN 20) is bridged over bridge-domain
10. On egress at the switchport, a VLAN tag corresponding to the bridge-domain (VLAN 10) is pushed,
and a double-tagged packet (VLAN 10 and VLAN 20) is sent out on the switchport.
Figure 11-11
Untagged
After ingress at the switchport, the untagged packet is bridged over bridge-domain 10. On egress at the
EFP with no rewrite, there is an encapsulation mismatch because the bridged packet is untagged and the
encapsulation is dot1q 10. Therefore, the packet is dropped.
The same scenario applies when the switchport trunk is configured with the access VLAN ID or native
VLAN ID.
Cisco ME 3800X and 3600X Switch Software Configuration Guide
11-28
Single-tagged Traffic Between a Switchport and an EFP with no Rewrite
10
Switchport trunk
Single-tagged and Double-tagged Traffic Between a Switchport and an EFP with no
Rewrite
20
Switchport trunk
Untagged Traffic From a Switchport (with Native or Access VLAN) to an EFP with No
Rewrite
Switchport trunk
native vlan 10
or
Switchport access
access vlan 10
Chapter 11
Bridge domain
Service instance 1 ethernet
10
encapsulation dot1q10
bridge-domain 10
Bridge domain
Service instance 1 ethernet
10
encapsulation dot1q10
bridge-domain 10
Bridge domain
Service instance 1 ethernet
encapsulation dot1q10
10
bridge-domain 10
Configuring Ethernet Virtual Connections (EVCs)
Packet is dropped
due to encapsulation
mismatch
20
Packet is dropped
due to encapsulation
mismatch
OL-23400-01