Crossover Cables:
- way in which hubs can connect to each other
- reverses the sending and receiving pairs on one end of the cale
- connects to a regular port on each hub
- never connect two hubs by their uplink ports with a straight-through cable
Bridges:
- acts like a repeater or hub to connect two ethernet segments
- filters and forwards traffic between those segments based on the MAC addresses of the computers on those segments
- initially behaves exactly like a repeater
- however it monitors and records the network traffic
- mainly used in wireless networks
Switched Ethernet:
Trouble With Hubs:
- can only have one message on the wire at any time
Switches to the Rescue:
- create point-to-point connections between two computers
- copies the source MAC addresses and quickly creates a table of MAC addresses of each connected computer (Source Address Table)
- switch acts like a telephone operator
- can buffer incoming crames
- also known as a broadcast domain
Spanning Tree Protocol:
- switching loops: redundant connections in a network
- created to determine things like the distances between them
Troubleshooting Hubs and Switches:
- problems fall into three categories
- Obvious physical damage
- Dead ports
- general flakiness
It is rather challenging to keep up in an industry that changes so fast. Matt told me recently that crossover cables are no longer necessary, since ethernet ports on current switches and routers auto detect the kind of cable attached and auto configure switching (which has the two output wires going to the two input wires on the other end) electronically.
ReplyDeletePay attention to the spanning tree protocol. I've seen many a switching loop cause lots of difficult to detect problems.