Example: I have an IPv4 network, and you have an IPv4 network, and we want to talk to each other. But there's no IPv4 network between us. We need to tunnel our networks somehow through whatever is between us so that we can network to each other. That in between network could be anything, NetBEUI, IPX/SPX, IPv6, whatever. As long as we tunnel through it, our IPv4 networks can see each other (but not the network inbetween).

Interesting.

@Dashrender said in IPv6 Subnet Masks - CompTIA Network+ N10-007 Prof. Messer:

It's absolutely true that IPv6 gives us billions and billions of small networks worth of IPs(each of those smalls being likely larger than the full IPv4)

Right, both are just a flexible pool. One is just way, way bigger.

In big companies how use VoIP for production for example, this is a most, QoS needs to be very well deployed, to improve users/clients experience using the phone.

@mary said in Configuring IPv6 - CompTIA Network+ N10-007 Prof Messer:

When using ipconfig on a network I've seen the IPV4 and IPV6 addresses shown at the same workstation. Sometimes it shows IPV4 (preferred). Why is that?

I don't have a specific reasoning - but I'm guessing it's because the computer received a DHCP reply on IPv4 - so the computer assumes that IPv4 is the primary way this network wants to communicate.

@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

this is amazingly didactical... really enjoy this.

This video was a great introduction to networks. I like the description of the moving truck, it gives an image to start.

taking a few mins to watch this!

@coliver said in CentOS can be stupid as well.:

I find a good yum clean all tends to fix these types of errors.

Yep. I mostly just wanted to point out that even the OS myself and @scottalanmiller are always recommending can do dumb things from time to time as well.

@brianlittlejohn said:

@Dashrender Here is the generalized spreadsheet I put together, once I'm assigned the /48 block from the ISP I fill it in and it auto populates everywhere else on the spreadsheet.

https://www.dropbox.com/s/69ct5bzfgzuqfne/IPV6 Plan - Generic.xlsx?dl=0

Cool DropBox can view Excel sheets in the browser.

Thanks

@JaredBusch said:

@Dashrender said:

I'll consider changing it when I move to the flat network...

You are not on a flat network? That is how it works. You can have as many DHCP servers as you want as long as they do not see each other.

No, I have several subnets. The networks see each other through a router.

I'm not sure what you mean that you can have many DHCP servers as long as they don't see each other?

In my current setup, at this branch location of 10 PC's and 16 phones I have two DHCP servers. Each provide IPs for a different range in the same subnet. The Mitel PBX has a DHCP server but only responds to Mac addresses belonging to Mitel phones. The windows DHCP will respond to everything. My question was - what happens if the Windows server responds to a phone faster than the Mitel DHCP server? I'm guessing the phone wouldn't work.

This branch will probably always be on a different subnet (local to that location), but my main office has 5 /24 subnets.. I'd like to move them to one /22 subnet.

@DustinB3403 said:

They're already spending a ton of money to continue to support IPv4 because of NAT, and the requirement of both types being able to talk to each other.

The cost analysis is probably saying that this process is still less expensive then going all in on IPv6.

@RAM. said:

@scottalanmiller said:

@RAM. said:

I'm not sure why we haven't switched to IPv6 sooner, sure its a little more complex in terms of proper notation and subnetting, but its more secure as a whole, and offers much greater scalability.

Because it isn't available. Almost no ISP gives you an IPv6 address. If we had good access to IPv6 for all of our home users we would switch.

We've been using IPv6 on our Pertino network for a while.

I was referring to the collective sense of the word "we" which incorporated ISP's

Ah ha