Join Greg Sowell for an in-depth discussion in this video Packets and frames, part of Networking Foundations: Protocols and CLI Tools.
- [Voiceover] When working with addressing…and information flow, I tend to spend a significant…amount of time in layers two and three,…which are data link and network, respectively.…Layer two refers to communication between…devices on a common switched infrastructure.…This layer is best known for…switches and switching.…Each device uses a media access control…or MAC address.…This layer deals only with switching,…so frames don't really care about…the encapsulated IP addresses they are transferring.…Layer three refers to sending information…via IP address.…
This layer is best known…for routers and routing.…As information passes from router to router…on its way to a destination,…it will encapsulate from layer three,…to two, then to one as it is transmitted…from one router to the other.…When it enters a router,…it will decapsulate back up from layer one,…to two, and then to three.…It will then do a lookup on the layer three…information to see where to…forward the packet, then repeat the process.…As information moves up and down…
Protocols are the lifeblood of modern communication. By the end of this course, you'll know what you need to troubleshoot any network connection and keep the communication flowing.
Note: This course maps to domain 3 of the MTA Networking Fundamentals exam.
- Identify reasons why connectionless transmissions are faster.
- Determine what type of attack a gratuitous ARP announcing itself as a legitimate host indicates.
- State what IGMP snooping is useful for.
- Describe the best approach to use FTP to view and rename files on a server when your client is behind a firewall.
- Assess whether SSH is natively supported on Windows or not.
- List good uses for the arp command.