STP traffic flow

[lerner cisco]

All,

Got an below setup I am looking confirmation its works , your inputs please

   Sw1 - core  <------------------- trunk ----------- ----------------->sw2 core

   !                                                                                                          !

   !                                                                                                            !

  !                                                                                                             !

   Distribution L3 switch1   ---- no back to back connection --     Distribution L3 switch2

               !                                                               !

              trunk                                                trunk                                                      

                !                                                              !

                    access layer switch  sw1 - trunk connection to distribution switches

1)  I have core switches  ( SW1 and SW2 ) connected to distribution switches ( Distribution L3  SW1 and SW2 ) the port configured with trunk and L3 interface vlan 40  , the vlan 40 forming EIGRP neighbour ship with distribution switches , so port acting as L2 and L3 . also HSRP  vlan 40 configured  active ( sw1) standby ( sw2)

2)  distribution switches - connected to core switches with  trunk  & int vlan 40 forming EIGRP neighbour ship with both core switches - no hsrp vlan 40 configured on the distribution switches

4) access layer switch - trunk  connected to distribution switches and  L2  vlan 40 allowed . the gateway for this switch now is on the core switches  active HSRP vlan 40 IP

5) at access switch  the port connected Distribution sw1 - STP  FWD state , the other port in BLK state

would like to check with you , if connection made shut between access switch to distribution switch 1 , STP will remove seond port from BLK state and put in forwarding state &

traffic  will hit to the core sw2 and reach the gateway  HSRP active ip address at Core sw1

[Tom Watts · Accepted solution]

I'd say it should work fine provided the EIGRP path cost is consistent to your switch bridge ID for the desginated paths. If you're running equal cost path and default bridge ID, it may cause some weird paths by default so I think that is your primary consideration.