Hello,Half duplex means that it is sending and listening at the same time. With a hub you have more than one device that shares the medium. It is statistically possible to have to station that will listen and start sending a packet at the same time...
Hello Marcos,It is true that with private addresses, you could use a full class C to address a point-to-point but that would be different with public addresses.It is just a better technic to addess point-to-point with a /30.Nadine.
Hello Jason,I was referring to the 2600 family of routers. The 2621xm has 2 fastethernet interface that can be trunk with the switches. It also permit you to add a network module in the futur. Regards,Nadine.