STP for a beginner

[joshhboss]

the switches in the picture are how they are connected now.. the internet starts on switch 201.. but it goes through 202 to arrive finally at 203.. when really i think the traffic would be better sent directly to 203 instead of hoping through 202.. i do have a fiber there.. what i would like to do is have all fibers connected and set it up so switch 201 uses the fiber connecting directly to 203 to sent its traffic.. and if something happens to that link.. ok then 202 begins to work.. i assume its simple spanning tree..

I have recreated this setup in packet tracer and i have only gotten as far as the internet switch to put 

ShedSwitch(config)#spanning-tree vlan 50 root primary

but i do not know what to do on the other switches.. and do i need to do this for all the vlans? 

[luis_cordova]

Hi @joshhboss 

Indeed, I recommend that the switch closest to the internet remains as root, as that ensures that none of its ports go to Block state.
I also recommend that this switch be the root for all vlan present in your network.

regards

[pmckenzie]

You are doing great Josh almost there

You need to ensure all your switches are using the same STP protocol and have same fibre connection

then

There are a lot of articles on different flavours of STP and what each stage is about for example

https://www.geeksforgeeks.org/root-bridge-election-in-spanning-tree-protocol/

Note the part about different cable and their priorities

Root port – The port which receives the best BPDU on non root bridge. Criteria for selecting root port:

1. Lowest path cost to reach root bridge
2. Lowest sender Bridge I’d
3. Lowest sender port I’d

[joshhboss]

@pmckenzie the switch 201 is the one closest to the internet. so is that not the one i want as root primary.. and i am using vlans.. 50,69,75,200,254,400. And with the commands that you have issued there, the switches will already know that the best link to use for the computers on switch 203 would be the link from 201 to 203.? there isnt anything i need to do to the priority. i asked someone on the ubiquiti forums just to take a chance someone there might know. and someone mention that i should make the cost of the link on 203 higher? dont know ? is the that 

JoshSw1(config)#spanning-tree pathcost method ?
  long   Use 32 bit based values for default port path costs
  short  Use 16 bit based values for default port path costs

i get stuck there..  oh and that JoshSw1 is my old school 3560 Series PoE-8.. lol .. cause i cant find a small cisco poe gigabit with cli..

but its where i learn.. 

[pmckenzie · Accepted solution]