Figure below shows a LAN topology with bridges to interconne

Figure below shows a LAN topology with bridges to interconnect different LAN segments. Spanning tree algorithm is used for deciding the forwarding path. Please show the resulting spanning tree and specify the path followed by a frame from LAN segment 4 to LAN segment 2. Assume all links have the same cost.

LAN7 2 B6 B4 B5 LANS LAN4 LAN6 2 B1 B3 LAN3 1 B2 LAN2 LANI

Solution

Spanning tree protocol is used to avoid loops in a network between inter connected network devices.

As shown in the picture this topology may create two Network loops , One in between B1,B4 and B5 .And another one is due to the complete circuit which is formed by B2 ,B1 and B3.

To Avoid these loops we simply run the STP which is also by default active on network devices.Hence it could block Port number 2 in B2 Bridge or Port number 3 , and port in B4 and B5.

If a frame started travelling from LAN 4 the best shortest route is through B1 ,LAN3 to B2 port number-2 then it wil reach LAN 2 easily . As we know all the routes have equal cost.