Sunday, September 16, 2012

Lesson 12 (ICND 1 1.9) Describe the components required for network and Internet communications

This is a pretty vague objective and could encompass any number of hardware or software items.  For now we will stick with the basics. A lot of this will be review from Lesson 1 as there is a lot of overlap.  Feel free to visit lesson 1 again for review.

To communicate on a network you first need an originating host.  That host can be a laptop, a desktop, a tablet, a smart phone, an IP phone, a server, or any number of devices with an internet protocol (TCP/IP) address.

Next, you'll need a destination host to communicate with.  That destination host may be a web server in Singapore, the file server in your datacenter, or a laptop in the cubicle next to you.

For that host to communicate on the network to reach this intended destination, you'll need to have a communications medium, that medium can be 802.11 wireless, 3G or 4G cellular networks,  and copper or optical wired ethernet.

Local communications typically will remain on the local area network (LAN) comprised of switches, distant locations will typically require a WAN connection comprised of routers.

If you are looking to get to a destination on the public Internet, you will need to go through a default gateway.  A default gateway is the router closest to you.  It is literally the gateway you must go through to get to the outside.

There may be any number of routers and communications mediums between your local host and the destination.

Here's a video that explains the overall process.Again, this objective has a lot of overlap with Lesson 1, so it's mostly a review.  Many of the blanks will be filled in subsequent videos.




Tuesday, September 11, 2012

Lesson 11 (ICND1 1.8) Determine the path between two hosts across a network

When you are asked to determine a path between two hosts in a network, you will most often accomplish this through the traceroute command.

Here's a great video by Cbtnuggets which explains traceroute in detail.