If four switches are connected to each other
back to back with trunk configured.
Switches connected are like this :
And if the Switch 4 is the STP root bridge.
VLAN's are not configured on all switches are and those are running in default VLAN1.
Now if PC1 from swicth 1 pings to PC2 from switch 2.
CASE 1 . Is is so that frame from PC1 will travel upto root bridge that is switch 4, and then gets redirected back towards swicth2.
CASE 2. The frame from PC1 will travel to swicth number 2 , there is will find the PC2 mac address and swicth 2 will forward that frame to PC2.
Keeping aside the initial ARP broad cast.
Which case is correct.
Please share the experience.
The Case 2 is correct. The STP does not change the way how switches forward frames. That principle remains even with STP: whenever a switch receives a frame, it tries to find its destination MAC in its switching table. If it finds it, it forwards the frame out that port only. If it does not find the destination MAC, it will forward the frame out every other port. With STP, this procedure changes only slightly: the frame will be processed only if it is received on a port in the Forwarding state, and it will be fowarded out only through ports in the Forwarding state. However, the frame absolutely does not have to go all the way to the root bridge and back.