Join Greg Sowell for an in-depth discussion in this video Port addresses, part of Networking Foundations: Protocols and CLI Tools.
- Layer four of the OSI model, transport,…uses a 16-bit number, known as a port,…to facilitate end point communication.…TCP and UDP both open up lines of communications…using ports.…Applications will open up a port and wait…for an incoming connection.…This is also referred to as listening.…For well known applications,…these will be well known port numbers like,…port 80 for HTTP, or 443 for HTTPS.…Once the client application connects…on the well known port the server…will sometimes shift the client to a different port…to complete the transaction.…
Well known ports are generally less than 1024.…Ephemeral ports are those above 1024,…and are usually used for short-term communications…by clients.…Whenever a packet is created and sent…the header in the packet will specify both the source…and the destination port.…Since the port number is 16-bit…it can be 0-65535.…TCP can't use port 0, as it is reserved.…With UDP, source port number is optional,…and a value of zero means no port is used.…
An internet socket is created using…
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.