ZyXEL Communications GS2200 Series, Руководство пользователя

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Chapter 27 Layer 2 Protocol Tunneling
GS2200 Series User’s Guide
214
To emulate a point-to-point topology between two customer switches at different sites, such as A
and B, you can enable protocol tunneling on edge switches 1 and 2 for PAgP (Port Aggregation
Protocol), LACP or UDLD (UniDirectional Link Detection).
Figure 140
L2PT Network Example
27.1.2.1 Layer 2 Protocol Tunneling Mode
Each port can have two layer 2 protocol tunneling modes, Access and Tunnel.
• The Access port is an ingress port on the service provider's edge device (1 or 2 in Figure 140 on
page 214 ) and connected to a customer switch (A or B). Incoming layer 2 protocol packets
received on an access port are encapsulated and forwarded to the tunnel ports.
• The Tunnel port is an egress port at the edge of the service provider's network and connected to
another service provider’s switch. Incoming encapsulated layer 2 protocol packets received on a
tunnel port are decapsulated and sent to an access port.
1
2
A
B
Service Provider's
Network
C
D
STP
STP
STP