Introduction to IP - CompTIA Network+ N10-007 Prof Messer





  • Can someone go over any issues they may have with ports? From the way it is explained it doesn't seem like it would be an issue, so I'm curious if this is the case.



  • @mary said in Introduction to IP - CompTIA Network+ N10-007 Prof Messer:

    Can someone go over any issues they may have with ports? From the way it is explained it doesn't seem like it would be an issue, so I'm curious if this is the case.

    Ports are like the "suite number" in an address. Nothing more. So there really isn't a concept of "problems with ports".

    If you send a letter to....

    123 Friendly Lane
    Suite 18
    Cooperstown, NY

    Then 123 Friendly Lane, Cooperstown NY is the IP address, and Suite 18 is the port. That's really all that there is to it.

    Now, there are "well known ports". Ports that are commonly assigned for certain tasks. Like port 25 is used for email, port 22 for SSH, port 3389 for Remote Desktop, etc. But those are just conventions and nothing else. Just like if Suite 10 was "almost always" the real estate office for the building.



  • Humans do tend to get confused a bit on ports. Here are some things why...

    • TCP and UDP have the same port ranges but are different protocols and TCP ports are unrelated to UDP ports. So TCP Port 22 can be doing one thing and UDP port 22 something totally different.
    • Ports under 1024 are traditionally designated by the operating system as protected and require admin level to open. Ports at 1024 or higher can be opened by anyone. But that is an operating system thing, not a networking thing. But important to know.
    • TCP and UDP are not the only protocols and not every situation has a port. ICMP doesn't use TCP or UDP and does not use ports at all, for example.
    • TCP is connection based, UDP is connectionless. So people often get confused with UDP because you can't "open a connection" to see if it is working. Even people with 20 years of experience forget this constantly and fail to troubleshoot.


  • @scottalanmiller said in Introduction to IP - CompTIA Network+ N10-007 Prof Messer:

    Humans do tend to get confused a bit on ports. Here are some things why...

    • TCP and UDP have the same port ranges but are different protocols and TCP ports are unrelated to UDP ports. So TCP Port 22 can be doing one thing and UDP port 22 something totally different.
    • Ports under 1024 are traditionally designated by the operating system as protected and require admin level to open. Ports at 1024 or higher can be opened by anyone. But that is an operating system thing, not a networking thing. But important to know.
    • TCP and UDP are not the only protocols and not every situation has a port. ICMP doesn't use TCP or UDP and does not use ports at all, for example.
    • TCP is connection based, UDP is connectionless. So people often get confused with UDP because you can't "open a connection" to see if it is working. Even people with 20 years of experience forget this constantly and fail to troubleshoot.

    I'll tell you a UDP joke, but I'm not sure you'd get it.
    Might tell you another UDP joke, but I'm not sure you'd get that either.
    But then, I'll tell you a TCP joke, and I know you'll get that one.



  • @FiyaFly said in Introduction to IP - CompTIA Network+ N10-007 Prof Messer:

    @scottalanmiller said in Introduction to IP - CompTIA Network+ N10-007 Prof Messer:

    Humans do tend to get confused a bit on ports. Here are some things why...

    • TCP and UDP have the same port ranges but are different protocols and TCP ports are unrelated to UDP ports. So TCP Port 22 can be doing one thing and UDP port 22 something totally different.
    • Ports under 1024 are traditionally designated by the operating system as protected and require admin level to open. Ports at 1024 or higher can be opened by anyone. But that is an operating system thing, not a networking thing. But important to know.
    • TCP and UDP are not the only protocols and not every situation has a port. ICMP doesn't use TCP or UDP and does not use ports at all, for example.
    • TCP is connection based, UDP is connectionless. So people often get confused with UDP because you can't "open a connection" to see if it is working. Even people with 20 years of experience forget this constantly and fail to troubleshoot.

    I'll tell you a UDP joke, but I'm not sure you'd get it.
    Might tell you another UDP joke, but I'm not sure you'd get that either.
    But then, I'll tell you a TCP joke, and I know you'll get that one.

    I laughed out loud at my desk and my coworker didnt understand the joke.
    HA