@mary said in Software-Defined Networking - CompTIA Network+ N10-007 Prof Messer: Is there specific software that is used for creating a virtual environment? SDN refers to a great number of potential solutions. In most cases, it is software built into the hardware. So Cisco, Juniper, Brocade and other networking makers offer software solutions, often that have no particular name. They are just the SDN options of that gear. Pure software does exist and a common example of it is ZeroTier which is designed as a complete virtual networking layer on top of your physical network and has no interaction with the underlying hardware so it completely agnostic.

@mary said in Circuit Switching and Packet Switching - CompTIA Network+ N10-007 Prof Messer: Is there anything not considered packet switching? Yes, the most common example is the voice network (the PSTN / Public Switched Telephone Network). It establishes a "circuit" for every call, and it is permanent until that call ends. It switches on a "call by call" basis. Every packet associated with that call takes the same path. It is almost always considered archaic to use circuit switching, it is rarely useful or efficient. It was popular in the "pre-data" era of networking when it was audio and video, generally analogue, going over the path rather than individual packets. Now that we have packetized data and the power to evaluate the route every packet, there is little to no purpose for circuit switching.

@mary said in Access Control Lists - CompTIA Network+ N10-007 Prof Messer: Is there a way to deny all incoming traffic to your firewall? Sure. But if you think about it, you'd absolutely never want this. This would be the same as disconnecting the network. If you wanted to do this, you would simply unplug the network instead (as that is more reliable.) The only reason to truly "deny all" is to go offline. And if you want to be offline you logically want it to be really reliable and since you'd want no traffic to make it no matter what in that situation, pulling the plug is the better choice 99.99% of the time.

@mary said in Network Address Translation - CompTIA Network+ N10-007 Prof Messer: Is there any kind of slowdown when using just one port if you are getting a lot of traffic? No not really. The most commonly used ports are 80 and 443. They process quite a bit of traffic on your average workstation. In fact, most servers are designed to work with a single port or just a handful of ports open. For custom applications using a specific port makes it easier to troubleshoot issues and restricts non application traffic. Many apps are defaulting to 443 these days. Although, keep in mind SSL /TLS can operate on other ports.

@hobbit666 said in SAMIT on Huawei vs Google: One thing I don't get yet is my have Xiaomi, Umidigi and other manufactures from that side of the world not been effect by all this stuff with the US? My thoughts would be if the government have been asking Huawei to but spying/data harvesting stuff in gear wouldn't they be asking all manufacturers? If they go after "all" it would over expose the falseness of the whole thing.

It only kicks in when a pipe has hit saturation. Even if you're at 99% bandwidth, there would be no prioritizing because the packets would just flow in the order they are received. So the answer is, it totally depends if your pipe is ever saturated.

@mary said in IPv4 and IPv6 Addressing - CompTIA Network+ N10-007 Prof Messer: If you are using :: to abbreviate sets of 2 or more zeros, how can you tell how many there are? In the example he condensed 3 sets down to ::? IPv6 always has 8 sets of 4 numbers for addressing. So it should be easy to figure out with a little math. IE: FABD:4976:5AC3:: would mean that 5 more sets of 4 zeros is tacked on FABD:4976:5AC3:0000:0000:0000:0000:0000

He mentioned proprietary protocols. Do you always have the option to choose between the standard and proprietary or do some force you to use the proprietary?

@mary said in IGP and EGP - CompTIA Network+ N10-007: Hiw important are the different types of protocols for IPV4 and 6? Pretty important, but not things any normal IT pro will ever see. Routing protocols are only modified by large companies, and only by dedicated network admin staff.

@mary said in Static and Dynamic Routing - CompTIA Network+ N10-007 Prof Messer: If you can set a default route, why would you use static over dynamic? Static routes require a human to modify them anytime anything changes. So, for example, the route you want fails because a device dies. If you have static routing, then you simply go offline until you go and change the route to something else manually. When the device is repaired, you won't go back to the optimum route until such time as someone manually puts it back. With dynamic routing, the protocols look for the best routes at all time and can not just adjust for failure conditions, but can also detect new routes that are better when they appear, go back to repaired routes, detect congestion and adjust routes based on temporary traffic conditions, etc. Think of one as having a map telling you how to get from point A to point B and if there is road construction or loads of traffic or an accident, that you just have to sit there until your route clears up. And dynamic routing like a GPS that adjusts based on real world conditions and gives you an alternative route should your main one be blocked or slow.

@mary said in Switch Interface Properties - CompTIA Network+ N10-007 Prof Messer: Are port mirrors common for companies that monitor what employees are doing on the network or is something else used? No, that would be insanely impractical. A port mirror doesn't give you a copy of what someone is actually doing, it gives you a copy of the network traffic. Which is a butt load of disconnected data. It's not like you would know what the end user was doing, only what was being transferred on the wire. If you think about what you'd see on the wire... a single file transfer or LAN based action might generate a huge amount of traffic. Or going to a website might create a bunch of unintentional traffic from ads that aren't something that the end user cared about. Or a website or app open in the background might generate gops of traffic for something that isn't being used. It would be able to tell you if the person is on YouTube or Spotify, but would not tell you what they are doing that for or if they are actively "using" that thing. Basically you'd be flooded with information that would take ages to sort through, and the resulting information would tell you essentially nothing about what the end user was doing.

@mary said in Spanning Tree Protocol - CompTIA Network+ N10-007 Prof Messer: If you have a bad switch are you informed in any way? Generally no. "Bad switch" is an awfully general thing. Most switches are "dumb", just simple boxes with zero communications with the outside world. A good, managed switch might have some alerting, depending on how it fails, and how you are monitoring it. the problem with any device failing is that it generally does not know that it is failing or it wouldn't fail. Switches are very core so rarely can detect their own failures. Mostly you detect switch failures from there being problems on the network and just testing. These days switches have a tendency to just die, or just work. In the past you used to have a port here or there that would fail. Switches failing can do weird things, but often just give up and quit on you.

Is there a limit to how many trunks you can use?

It's more purpose based. Unicast is for normal communications. Broadcast is normally reserved for special cases like DHCP where there is no way to do unicast.

@mary said in Common Ports - CompTIA Network+ N10-007 Prof Messer: @scottalanmiller makes sense. He did say outgoing to a DNS server. Thanks UDP itself has no connections, but that doesn't mean that a protocol running on top of it can't have its own connections. TCP makes connections for you, UDP requires you to do it yourself (if you want them.) So important to know that UDP itself does one thing, but can be used as a tool to make other things.

@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

@mary said in Windows HomeGroups, WorkGroups, and Domains - CompTIA A+ 220-1002 Prof Messer: Is there any alternative to home group now that it isn't available on Windows 10? Also why would you use workgroup instead of Windows Domain? Is it a cost issue? "Home Group" was just a fancy name for network sharing without AD on Windows computers.

@mary said in Windows Control Panel - CompTIA A+ 220-1002 Prof Messer: This may be basic but, can cookies damage your system in anyway? It's one of those things that a lot of sites require you to accept, and an average user just accepts them. So the cookie itself is just a text file. A tiny one. That's it. So the cookie itself does nothing. The issues are if the cookie has something in the text and a browser reads it and does something it shouldn't because of it. But realistically, that's not going to happen. The main concerns around cookies are that they help people to track you, but you need to be tracked. We've been conditioned to thinking that being tracked is a bad thing, but cookies are what lets us track you from post to post here in RoIT for example.

Pretty useful stuff. I played around with some of the commands on my laptop.

@mary said in Windows Task Manager - CompTIA A+ 220-1002 Prof Messer: Do any of you use task manager to troubleshoot what if there is an issue with a PC? I'm trying to get a sense of the steps people go through. Constantly. If working on Windows, it's the "go to" starting point to "see what is going on." It's not a once in a while tool, it's the "might as well just always start there" tool. It gives you a quick glance to see what the system itself is doing. If CPU or RAM is maxed out, or a process list looks crazy, that's almost always what is wrong no matter what it is that you came to look at! I mean if I'm looking for a missing folder of cat pictures, I don't open the task manager first. Nor if I'm installing a new printer. But if I am troubleshooting anything going on with the system, that's the first place to look. The Resource Monitor is also pretty fantastic.

Pretty straightforward.

@scottalanmiller said in Windows Firewall with Advanced Security - CompTIA A+ 220-1002 Prof Messer: @JaredBusch well it's good to be explicit that Windows Defender and Windows Defender Firewall are two different products. But also Windows Firewall isn't a real name, either. Windows Defender Firewall is the name of the Windows firewall. So using "Windows Firewall" or "firewall by Windows Defender" are essentially the same - lose descriptions of the brand name. All make sense. Good to remember that the pieces are discrete. The best full statement is "the Windows firewall is Windows Defender Firewall." True, but until Windows 10, it was simply called Windows Firewall. So that is a correct legacy term. Vista introduced the longer term Windows Firewall with Advanced Security in the MMC snap in. It stayed those two terms until Windows 10.

@mary said in Windows Administrative Tools - CompTIA A+ 220-1002 Prof Messer: Is there a list anywhere of the Windows command prompts, or do you usually look at the help to look at options? I realize the more seasoned IT person would have a lot of these committed to memory, but just starting out this is a bit overwhelming. There seem to be a lot of them to keep track of. Kind of. There are some built in tools to the shell itself, and some standard Windows tools that you can call. but keep in mind that you can add an unlimited number of additional ones, because all you are doing is calling installed applications. So while there are lists of the ones built in, most people have loads and loads of ones that are not.

@mary said in Network Command Line Tools - CompTIA A+ 220-1002 Prof Messer: Is it ok to have any packet loss when pinging another computer? It's not a crime or anything There is always "some" packet loss, but in a healthy network it is super low, like one out of one hundred thousands packets. If you are doing a ping and seeing packets missed regularly, something is wrong. On a wired network, this implies bad equipment, cabling, or EM interference. On wireless it means your signal isn't clean. Obviously wifi is going to lose packets way more than a cabled connection, and copper way more than optical. But it should still be essentially zero on a healthy network.