Your switch has a port status LED that is alternating between green and amber. What could this indicate?

First, if you have two hosts directly connected, as shown in the graphic, then you need a crossover cable. A straight-through cable won't work. Second, the hosts have different masks, which puts them in different subnets. The easy solution is just to set both masks to 255.255.255.0 (/24).

Routers provide packet switching, packet filtering, internetwork communication, and path selection.

The key is "there are no free ports" on your router. Only Frame Relay can provide a connection to multiple locations with one interface, and in an economical manner no less.

PPP is your only option, as HDLC and Frame Relay do not support these types of business requirements. PPP provides dynamic addressing, authentication using PAP or CHAP, and callback services.

If you save a configuration and reload the router and it comes up either in setup mode or as a blank configuration, chances are you have the configuration register setting incorrect.

Please do not freak out because ATM is an answer to this question. ATM is not covered in depth on the CCNA exam. PPP is mostly used for dial-up (async) services, but ATM could be used as well, though it typically is not used anymore since PPP is so efficient.

It is very important to remember when studying the CCNA exam objectives, and when configuring Frame Relay with point-to-point subinterfaces, that you do not put an IP address on the physical interface.

The command debug ppp authentication will show you the authentication process that PPP uses between point-to-point connections.

The IEEE 802.11b standard provides a maximum data rate of up to 11Mbps.

Unlike full duplex, half-duplex Ethernet operates in a shared collision domain, and it has a lower effective throughput than full duplex.