I have a total of 9 Cisco Switches on my network. Below are the types of switches I am using:
Cisco 3550-12G (Used as the Core Switches. (I am using two for redundancy purposes)
Cisco 3550-24 port (Used as the DMZ Switches) (I am using two for redundancy purposes)
Cisco 3550-48 port (Used for the Subnet/LAN switches)
All switches on this network share a common VLAN for VTP. The common VLAN is VLAN 20, which is represented in the below network topology.
As you will see from the below network topology, I am using two Cisco 3550-12Gs for redundancy purposes. Right now all traffic is going out the Primary 3550-12G, but if I would shut that switch off, all traffic goes out the Secondary 3550-12G. Each subnet switch(3550-48) have two route statements to allow this.
All this is currently working and in production, but what I'm not sure about is if I have to do anything special with Spanning Tree Protocol. I know by default STP is enabled on Cisco Switches, but with all the redundant links I have, I afraid there may be some loops occuring. Does anyone have any input on how I should configure STP for my below network. Thanks.