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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter9 Creating and Maintai nin g VLA Ns Understanding VMPS
Understanding VMPS
The Catalyst 3550 switch acts as a client to the VMPS and communicates with it through the VLAN
Query Protocol (VQP). When the VMPS receives a VQP request from a client switch, it searches its
database for a MAC-address-to-VLAN mapping. The server response i s base d on t h is ma pp ing an d
whether or not the server is in secure mode. Secure mode determine s whe ther the server shuts down the
port when a VLAN is not allowed on it or just denies the port access to the VLAN.
In response to a request, the VMPS takes one of these actions:
•If the assigned VLAN is restricted to a group of ports, the VMPS verifies the requesting po rt against
this group and responds as follows:
–
If the VLAN is allowed on the port, the VMPS sends the VLAN name to the client in response.
–
If the VLAN is not allowed on the port and the VMPS is not in secure mod e, the VMPS se nd s
an access-denied response.
–
If the VLAN is not allowed on the port and the VMPS is in secure mode, the VMPS sends a
port-shutdown response.
•If the VLAN in the database does not match the current VLAN on the port and active hosts exist on
the port, the VMPS sends an access-denied or a port-shutdown response, depending on the secure
mode of the VMPS.
Step8 show running-config Verify your entries.
In the display, make sure that interfaces Fast Ethernet 0/1 and Fast
Ethernet 0/2 are configured as trunk ports.
Step9 show vlan When the trunk links come up, Switch 1 receives the VTP information
from the other switches. Verify that Switch 1 has learned the VLAN
configuration.
Step10 configure terminal Enter global configuration mode.
Step11 interface fastethernet 0/1 Enter interface configuration mode, and define Fast Ethernet port 0/1 as
the interface to set the STP cost.
Step12 spanning-tree vlan 2 cost 30 Set the spanning-tree path cost to 30 for VLAN 2.
Step13 spanning-tree vlan 3 cost 30 Set the spanning-tree path cost to 30 for VLAN 3.
Step14 spanning-tree vlan 4 cost 30 Set the spanning-tree path cost to 30 for VLAN 4.
Step15 end Return to global configuration mode.
Step16 Repeat Steps 9 through 11 on Switch 1 interface Fast Ethernet 0/2, and
set the spanning-tree path cost to 30 for VLANs 8, 9, and 10.
Step17 exit Return to privileged EXEC mode.
Step18 show running-config Verify your entries.
In the display, verify that the path costs are set correctly for interfaces
Fast Ethernet 0/1 and 0/2.
Step19 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose