I did some more research and it turns out that WiFi calling is using some familiar protocols but it's not the same as VoIP using SIP/RTP.

Actually another name for Wi-Fi Calling is the more official VoWiFi.
It's using a protocol called GAN (Generic Access Network) that is based on IMS, IPsec and ePDG. And IMS is using SIP for signaling.

Basically it's a way of sending the same packets that would go over the cell network over internet instead. It uses the SIM card for security and authentication. It's data is encapsulated in an IPsec tunnel - which is why it only works if IPsec ports and packets are allowed in the firewall.

Related technology that works in a very similar way is VoLTE, which is Voice over the 4G/LTE network.

@FATeknollogee said in Co-lo + 5 (or more) sites....connect 'em all:

@Pete-S said in Co-lo + 5 (or more) sites....connect 'em all:

But it's the fact that small routers have very weak CPUs but they can off load straight IPsec, when you are not doing packet inspection or anything that requires the CPU. However they can't off load OpenVPN.

Sounds like the choice should def be IPSec for less of a performance hit?

With an Edgerouter yes. You can read more here and see how much difference it makes.
https://help.ubnt.com/hc/en-us/articles/115006567467-EdgeRouter-Hardware-Offloading

Is it possible / bad practice to use the first address in the network, for instance 192.168.0.0 (netmask 255.255.255.0) ?

If I remember correctly a long time ago it wasn't possible but nowadays it is. I never use it but when you have small subnets like /29 it could be nice.

OK, I did some more research and made some test. I believe most people got this one wrong and for reasons that are historical.

Assume we have the network 192.168.1.0/24.
Subnet mask 255.255.255.0. The address range is 192.168.1.0 to 192.168.1.255.

192.168.1.0 is a valid host IP - contrary to what most people believe.
192.168.1.255 is reserved for directed broadcast.

Why?

An IP like 192.168.1.0 used to be excluded from use by a host in the past. This was obsoleted in conjunction with the introduction of classless subnets, CIDR. Mentioned in 1995, RFC 1878, which also obsoleted something related, which was the exclusion of certain subnets called subnet zero and the all-ones subnet.

In the past IPs like 192.168.1.0 has also been used as a broadcast address but that practice is also obsolete. RFC 1812 (also 1995) states that 192.168.1.255 should be used for directed broadcast in the 192.168.1.0/24 network and that 192.168.1.0 is forbidden to use for that purpose.

Problem when something becomes obsolete is that you still have old equipment, old protocols and old habits in use. So it takes many years before you can actually stop doing certain things that were needed in the past.

To test the state of things today I spun up some VMs. I used 172.16.0.0/24 as my network.

No problem setting 172.16.0.0 as IP address on CentOS or Debian for example. Everything works as you would expect.

You could however see some remnants of the past, like this:

As mentioned above, it was a long time since that was considered a broadcast address.

Windows 7 was however another story. You can't enter 172.16.0.0 as a valid IP address in network settings. But you can do it on the command line with netsh. And then it shows up as expected. Network works as expected too.

So all in all, it is technically OK to use the first IP as an host IP. It's not reserved anymore and hasn't been for more than two decades. Protocols that used that IP for broadcast or reserved for the network address are not in use anymore.

The biggest risk is probably to run into applications where they on purpose don't allow you to enter a specific "invalid" IP address.

That said, it would probably be very confusing for most people.

Since we're talking about VDI and thin clients...

I just now got around to hooking up a Raspberry Pi 4 to a 4K monitor. I've had it since July but only been running it headless.

Now I'm running RDP on Remmina and it actually pretty decent. It also works as a semi-fat client running light stuff such as office, watching youtube, news sites etc. Not as fast as an i3 or something with more horsepower but reasonably good.

Right now I have two Firefox windows with a couple of tabs open in each and running a RDP session with 2560x1440 resolution and have a couple of terminal windows open as well, a gimp file and looking at HD video with VLC over the network. Using about 1.5GB of RAM now. I'm running Raspian OS, which is Debian 10 with some tweaks.

It's the 4GB RAM version I have. But looking at the memory usage I think the 2GB RAM version would do fine in most cases as well.

2GB RAM version is $55 if you buy the bulk version. Add a suitable case $10, power supply $8, 8GB memory card $10.
Total cost around $85.

A compact printer has to do sharp turns. The older printer may have been a much larger model or had a completely different paper path, like some old inkjets.

A printer that has the ability to feed the paper in a straight path is the best thing. When you open the "backdoor" that is what you have.

HP printer:

@scottalanmiller said in Making a Raspberry Pi 4 or Similar SBC Desktop:

@Pete-S said in Making a Raspberry Pi 4 or Similar SBC Desktop:

Right now the storage and the GPU performance is what holds the RPI4 back the most.

Maybe Raspberry Pi 5 will be it. (But I've been thinking that since the first Rasberry Pi, 7 or 8 years ago)

The GPU is plenty, I think, for me. Need extremely little. But the storage, that's a killer.

The GPU performance might not be a GPU performance problem itself but rather a lack of support in the GPU for decoding common video streams. For instance VP8/VP9 (WebM) are used in things like youtube, html5 video, video conferencing etc.

When the system encounters a video stream and it doesn't have hardware decoding support, it needs the power to decode it in real-time with the CPU or you end up with stuttering video. RPI 4 doesn't have that power on 1080p.

You can mount the filesystem of another server over SSH (using SFTP) both on linux and windows with sshfs (SSH File System).

On the Windows client you have to install:

• WinSfp - https://github.com/billziss-gh/winfsp/releases
• SSHFS-Win https://github.com/billziss-gh/sshfs-win/releases

To mount the server just map the network drive in the file explorer or with net use or whatever.
Mount the root directory with \\sshfs.r\user@host

On the linux client you mount it with the sshfs command.
Syntax: sshfs [user@]hostname:[directory] mountpoint
More on https://github.com/libfuse/sshfs

Thought I'll share since I did this today and thought it might be useful for others as well.

We use xenserver and xcp-ng hosts but we use the Windows client, aka Xencenter, to manage the hosts.

Xencenter is to xenserver/xcp-ng what virt-manager is to KVM - but Xencenter is more advanced and powerful.

It talks directly to the hosts on the hosts management interface using the embedded web service (xml-rpc) inside the host so no management VMs or anything is required. We access the hosts management interface over VPN.

The client itself is just a user interface and doesn't store anything so you can run multiple clients connected to the same hosts at the same time.

Xencenter client -> host

You can also combine it with Xen Orchestra which is a web application for managing the host and give additional functionality.

Web browser -> XO server -> host

Installing XCP-ng using a Windows PC.

This how to install XCP-ng and set up a VM using a Windows PC.

"XCP-ng" is the hypervisor and "XCP-ng Center" is the application that you can use to manage your XCP-ng server from your Windows PC. It's just a user interface so there is no hypervisor data stored on the Windows PC.

Prereqs

• Windows PC to work from.
• Server to install the hypervisor on.
  • Harddrive that is 46GB or larger, 70GB recommended.
  • More info here: https://docs.citrix.com/en-us/citrix-hypervisor/system-requirements.html
  • Monitor & keyboard if you're installing locally.
• USB media or remote out-of-band management on the server (iDrac, iLO, IPMI etc)

Step 1

Download ISO file for XCP-ng from https://xcp-ng.org/download
It's about 0.5 GB.

Step 2

Option 1 - Use USB stick

Create a bootable USB by

• Download a software to write to USB
  • Etcher - https://www.balena.io/etcher/
  • Rufus - https://rufus.ie/
• Install downloaded software
• Write XCP-ng ISO to USB stick
• Plug the USB stick into the server

Option 2 - Use remote server management (advanced option)

Prepare to install ISO remotely by

• Share the folder on your Windows PC where you have the XCP-ng ISO file.
• Prepare the server so that the management port is connected to the same network, it has an IP address and you have the login and password needed. Usually these settings are in the BIOS.
• Use your web browser to log into the servers IP and set up remote media pointing to the share on your Windows PC.

Step 3

Start up the server and install XCP-ng.
If it doesn't try to boot from the USB you need to go into the BIOS settings and change boot order.

Install is pretty straight forward except that you want to decide where you want to run your VMs. Either you can use the boot disk or if you can use another drive or raid array if you have that. Make sure you select thin provisioning, it may not be the default.

After XCP-ng is installed and the server rebooted you end up in a management console.

Note the hypervisors management network IP because you need it later.

Step 4

Download XCP-ng Center from https://github.com/xcp-ng/xenadmin/releases
Make sure you pick the latest release.

Step 5

Install XCP-ng Center.

XCP-ng Center is a fork of Citrix Xencenter and they are virtually identical.

Step 6

Inside XCP-ng Center pick "Add New Server" and enter the IP of the hypervisors management interface.
Now you can access the hypervisor settings from the XCP-ng Center.

Step 7

For you to be able to create a VM, XCP-ng needs a network share where it can access ISO files so that you can actually install an OS on your VM.
Create it it by

• Share a folder on your Windows PC or use local NAS if you have one.
• Copy or download the ISO of the OS you want to install and put it in the shared folder.
• In XCP-ng select "New Storage" and select ISO library and "Windows File Sharing". Enter location of your Windows share (easiest by using IP address and share name) and the login/password needed. If everything worked you should be able to see "SMB ISO library" in XCP-ng Center under your hypervisor. Inside that you'll see the ISO files stored on your shared Windows folder.

Step 8

Create a VM by clicking "New VM".
XCP-ng uses templates to set some basic minimum for the OS you intend to install. Pick the OS you are installing or the closest one to it. If you are installing something that is not there at all, you can pick "Other install media".

Select your ISO file when it asks for installation media. Pick how many cores and memory you need. And add a virtual disk or change the size of the one it suggests if needed. Then finally network settings and you are done.

XCP-ng will create the VM and automatically boot it up. In XCP-ng Center you can see the VM under your hypervisor in the left pane. If you click the "Console" tab you can see the screen and interact with the VM. Go through with the installation of the OS here.

Resources

If you get stuck you may want to have a look at Citrix documentation since XCP-ng is a fork of Citrix Hypervisor (earlier called Citrix Xenserver) so most things are identical.
https://docs.citrix.com/en-us/xencenter/current-release/

Normally you can do everything you need with the XCP-ng Center for your day to day things. If you however need to do more advanced things there are CLI commands you need to run on the hypervisor. For that the Citrix documentation is indispensible.

If you want to talk to others, XCP-ng has a user forum.
https://xcp-ng.org/forum/

There is also quite a few videos that will take you through installation and other things on youtube.
https://www.youtube.com/results?search_query=xcp-ng

Enjoy!

BTW, servers with AMD EPYC Rome CPUs have the capacity of two CPU Intel systems but the footprint and power of a 1U system.

Also for high density needs you can also go with multi-node servers, which will get you 4 two CPU servers on 2U format.

@hobbit666 said in Video editing - suggestions:

those little Mackie monitors are pretty sweet for the price. I'm looking at adding a pair to the current recording studio setup (or maybe the next size up).

Can I ask what purpose these "monitors" have in video editing, as when I googled then thinking they were Monitors lol I found they are speakers .

Sound is as important as video when doing video editing. That's why it's important to be able to hear exactly what the sound is. They are called monitors because that is the purpose - monitor the sound. Studio monitors differs from computer speakers because they are not designed to sound good - they are designed to sound as accurate as possible. Top of the line studio monitors can cost several thousands each.

This is what a typical video editing setup looks like:

The red "speakers" are the monitors.

5x faster sounds strange unless some weird testing was going on.

Maybe it was this below from wireguards site?
Well, you can't trust anyones benchmark when they don't know the difference between Mega (M) and milli (m). Seriously.

@brandon220 said in Which Nas OS?:

If you could manage shares from Cockpit it would be a game changer in the NAS category.

You can manage samba with Webmin. Redhat pushes Cockpit of course but Webmin has a lot more functionality.

If you want a turnkey solution you could install one of the fileserver images from Turnkeylinux.
You get SMB, SFTP, NFS, WebDAV, rsync and management with Webmin.
https://www.turnkeylinux.org/fileserver

@scottalanmiller

@openit said in Building your own lab:

@scottalanmiller @Pete-S
Do we have any complete post or article on ML which describes how to build a Lab with design, like server, switch etc. arrangement.

Really appreciate, if someone can provide any links, which gives complete lab design, to prepare me as a good Windows System Administrator, which should include all tasks, activities a typical SysAdmin requires.

The idea is that if you set up everything, you have gained experienced and knowledge in a number of areas you would not get otherwise.

Much more valuable than following a post.

Otherwise you would need a whole series of posts and videos to get you from start to finish.

@siringo said in Windows Servers Archived onto Linux, suggestions/help pls:

I'm not a Linuxer

I think you are better of with vmware essentials. It's low cost and don't have all the bells and whistles but there is a lot of people in the "windows world" that can manage it and you don't need any linux knowledge at all.

We use xcp-ng & xenserver and while it has a windows client for managing that is really good, you still need to be able to do things in linux to get by. Same thing with proxmox.

So for a windows shop with people that has windows knowledge, vmware makes more sense. Even if there are options that gives you more value for money.

But I suggest starting to play with some linux virtualization in your home lab.

I think it's easier using a dedicated firewall than a VM. Otherwise it's easy to lock yourself out since the VM is hosted on the machine you are doing admin work on.

For instance when upgrading the hypervisor, somethings goes wrong. Now you have no way to access anything anymore.

No, it's not the NIC.

It says PCIe error bus 0, device 6, function 0.

That's 00:06.0, and that is the PCI bridge E7520. Which I think is connected directly to the chipset on the CPU. Can't remember exactly what was on the CPU and the chipset back in those days.

Either way the motherboard/CPU is done.

Or I guess technically speaking a driver error caused by drive corruption could have caused the same error. After all it's the OS that gives the error message here.

As soon as you start adding stuff to the Raspberry PI 4 it stops making economic sense as a "workstation".

The 2GB or 4GB version with the cheapest case, power supply and SD-card still makes sense.

But when you add extras to be able to use SSDs and other stuff, you get into the same price range as lower end Intel NUCs and similar mini PCs. Unfortunately the raspberry pi 4 is not as fast and doesn't came with 3 year warranty etc. So it's less value for money.

If you on the other hand want a RPi4 to play around with ARM or to tinker with raspberry pi HATs and other hardware accessories, then of course it's the only choice.

Our go to for these use cases (low cost) has been Intel's J3455.