Cisco Catalyst 3120

16-9
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
OL-12247-01
Chapter 16 Configuring IEEE 802.1Q and Layer 2 Protocol Tunneling
Understanding Layer 2 Protocol Tunneling
Figure 16-4 Layer 2 Protocol Tunneling
Figure 16-5 Layer 2 Network Topology without Proper Convergence
In an SP network, you can use Layer 2 protocol tunneling to enhance the creation of EtherChannels by
emulating a point-to-point network topology. When you enable protocol tunneling (PAgP or LACP) on
the SP switch, remote customer switches receive the PDUs and can negotiate the automatic creation of
EtherChannels.
Customer X Site 2
VLANs 1 to 100
Customer Y Site 2
VLANs 1 to 200
Customer Y Site 1
VLANs 1 to 200
Customer X Site 1
VLANs 1 to 100
VLAN 30
Trunk
ports
Switch A
Trunk
ports
VLAN 30
VLAN 40
Service
provider
101822
Trunk
Asymmetric link
VLAN 30
VLAN 40
Trunk
ports
Switch B
Switch C
Switch D
Trunk
ports
101821
Customer X
virtual network
VLANs 1 to 100