25-08-2017, 09:32 PM
Connecting Devices
Connecting Devices.ppt (Size: 193.5 KB / Downloads: 27)
Gateway:
device sitting at a network node for interfacing with another network that uses different protocols.[Layer 4 to Layer 7]
Router:
a specialized network device that determines the next network point to which it can forward a data packet towards the destination of the packet. Unlike a gateway, it cannot interface different protocols.[layer 3]
SPANNING TREE ALGORITHM
There are two reasons to an extended LAN to have a loop in it.
the network is managed by more than one administrator; no single person knows the entire configuration of the network.
loops are built in to network on purpose to provide redundancy in case of failure.
Algorithm Selection
Labeled as B1, B2, B3
The algorithm first elects the bridge with smallest ID as the root of the spanning tree.
The root bridge always forwards frames out over all of its ports.
Each bridge computes the shortest path to root and notes which of its ports is on this path.
All the bridges connected to a given LAN elect a single designated bridge that will be responsible for forwarding frames toward the root bridge.