ZyXEL Communications 4728F User Manual

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Chapter 29 Layer 2 Protocol Tunneling
XGS-4526/4528F/4728F User’s Guide
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Use this row to make the setting the same for all ports. Use this row first 
and then make adjustments on a port-by-port basis. 
Note: Changes in this row are copied to all the ports as soon as you 
make them.
CDP
Select this option to have the Switch tunnel CDP (Cisco Discovery 
Protocol) packets so that other Cisco devices can be discovered through 
the service provider’s network.
STP
Select this option to have the Switch tunnel STP (Spanning Tree Protocol) 
packets so that STP can run properly across the service provider’s 
network and spanning trees can be set up based on bridge information 
from all (local and remote) networks.
VTP
Select this option to have the Switch tunnel VTP (VLAN Trunking Protocol) 
packets so that all customer switches can use consistent VLAN 
configuration through the service provider’s network.
Point to Point
The Switch supports PAgP (Port Aggregation Protocol), LACP (Link 
Aggregation Control Protocol) and UDLD (UniDirectional Link Detection) 
tunneling for a point-to-point topology.
Both PAgP and UDLD are Cisco’s proprietary data link layer protocols. 
PAgP is similar to LACP and used to set up a logical aggregation of 
Ethernet ports automatically. UDLD is to determine the link’s physical 
status and detect a unidirectional link.
PAGP
Select this option to have the Switch send PAgP packets to a peer to 
automatically negotiate and build a logical port aggregation.
LACP
Select this option to have the Switch send LACP packets to a peer to 
dynamically creates and manages trunk groups.
UDLD
Select this option to have the Switch send UDLD packets to a peer’s port 
it connected to monitor the physical status of a link.
Mode
Select Access to have the Switch encapsulate the incoming layer-2 
protocol packets and forward them to the tunnel port(s). Select Access 
for ingress ports at the edge of the service provider's network. 
Note: You can enable L2PT services for STP, LACP, VTP, CDP, 
UDLD, and PAGP on the access port(s) only. 
Select Tunnel for egress ports at the edge of the service provider's 
network. The Switch decapsulates the encapsulated layer-2 protocol 
packets received on a tunnel port by changing the destination MAC 
address to the original one, and then forward them to an access port. If 
the service(s) is not enabled on an access port, the protocol packets are 
dropped.
Apply
Click Apply to save your changes to the Switch’s run-time memory. The 
Switch loses these changes if it is turned off or loses power, so use the 
Save link on the top navigation panel to save your changes to the non-
volatile memory when you are done configuring.
Cancel
Click Cancel to begin configuring this screen afresh.
Table 92   Advanced Application > Layer 2 Protocol Tunneling  (continued)
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