ZyXEL Communications MES3500-24F User Manual

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Chapter 29 Layer 2 Protocol Tunneling
MES3500-24/24F User’s Guide
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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 90   
Advanced Application > Layer 2 Protocol Tunneling  (continued)
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