Specifying Drop And Shutdown Thresholds On Layer 2 Protocol Tunneling Ports - Cisco WS-C6506 Software Manual

Configuring Layer 2 Protocol Tunneling on the Switch
Figure 8-2
Layer 2 protocol tunneling access port
with 802.1Q tunneling
Customer

Specifying Drop and Shutdown Thresholds on Layer 2 Protocol Tunneling Ports

The shutdown threshold provides a type of rate limiting that prevents the edge switch from being
overwhelmed by attached customer switches. We recommend that you configure a shutdown threshold
value whenever you use Layer 2 protocol tunneling ports with 802.1Q tunneling.
We recommend that the maximum value for the shutdown threshold is 1000. This value reflects the
number of PDUs that an edge switch can handle per second (without dropping any) while performing
egress and ingress tunneling. For an edge switch, the shutdown threshold value determines the number
of Layer 2 protocol tunneling ports that can be connected to customer switches and the number of
customer VLANs per Layer 2 protocol tunneling port. In determining the recommended maximum value
of 1000, egress tunneling from the service provider network was also taken into consideration.
To determine the number of Layer 2 protocol tunneling ports (links) and the number of customer VLANs
per Layer 2 protocol tunneling port (VLANs per link) that an edge switch can handle, multiply the
number of Layer 2 protocol tunneling ports by the number of VLANs. The result should be less than or
equal to 1000. Some acceptable configurations are as follows:
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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
8-10
Layer 2 Protocol Tunneling on Trunks Network Example
Service provider
switch 1 switch A
Asymmetric
trunk
1 Layer 2 protocol tunneling port x 1000 VLANs
2 Layer 2 protocol tunneling ports x 500 VLANs
5 Layer 2 protocol tunneling ports x 200 VLANs
10 Layer 2 protocol tunneling ports x 100 VLANs
20 Layer 2 protocol tunneling ports x 50 VLANs
100 Layer 2 protocol tunneling ports x 10 VLANs
Chapter 8 Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling
Layer 2 protocol tunneling trunk port
(received packets must be
Service provider
switch B
Service provider
cloud
Trunk ports
(third party switch)
double tagged)
Customer
switch 2
Customer
switch 3
Customer
switch 4
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