An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer
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What exactly is a subnet mask? He skimmed right over it.
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@mary said in An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer:
What exactly is a subnet mask? He skimmed right over it.
The subnet mask is what determines the network portion versus the host portion of an IP address.
This is pretty straight forward when you us 24 bit (255.255.255.0) or 16 bit (255.255.0.0) or 8 bit (255.0.0.0) subnet masks because in the same octet where the zero is in the subnet mask, is where the host's (computer's) host portion is, and where the 255's are is the network address. Things become more complex when you have a subnet mask of any other bit length, because you have to use math to figure out what is the network versus what is the host portions.
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This may not make a lot of sense when starting out, but they do help as you continue.
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@scotth said in An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer:
This may not make a lot of sense when starting out, but they do help as you continue.
That cheat sheet is great, so long as you remember that the first and last addresses are not useable, and if the network communicates with the outside world, 1 address will be used for the gateway.
For example: My home lab I have 5 useable IP addresses. I know that means I'm using a /29 or 255.255.255.248 subnet, and the calculations aren't that hard, but having those cheat sheets available is just so much easier and quicker.
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@mary said in An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer:
What exactly is a subnet mask? He skimmed right over it.
So you have an "address" in IP world. It's a single address. One portion of the address tells you the network ID, one portion tells you the host ID within that network. The mask tells you which portion of the address is network and which portion is host ID. IP addressing is super bizarre in that it has this weird sliding scale with one address representing two different things that are not constant.
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Is IPv6 more common now? Or is IPv4 still more widely used?
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@connorsoliver said in An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer:
Is IPv6 more common now? Or is IPv4 still more widely used?
IPv4 is way more commonly used, but IPv6 is definitely out there and happening. IPv6 is found much more in companies, home users typically still use IPv4. but not all, definitely some residential carriers have moved to IPv6.
For the home LAN itself, and nearly all business networks, IPv4 is still used. There is little to no need for IPv6 on the LAN side of things, and might stay that way for a really, really long time. But OSes are starting to sneak IPv6 in for things and use it from time to time, so it's starting to creep up on us there, too.
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But realistically, if you started working in IT full time today, and did normal small business IT work all the time, you might not interact with IPv6 at all for a few years yet.
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So for now we don't use IPv6 on local network areas right? Maybe in the future?
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@brianwinkelmann said in An Overview of IPv4 and IPv6 - CompTIA A+ 220-1001 Prof Messer:
So for now we don't use IPv6 on local network areas right? Maybe in the future?
Some people do, but not many. Mostly people only move to it when they want public IP addresses. IPv4 works really well for internal addressing so while you are free to use whatever, most people (and companies) stick to IPv4 because it's well known, understood, and supported by any equipment that you have.
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taking a few mins to watch this!
