VM Networking ( Libvirt / Bridge ) 

This is such a great explanation. I've been doing this professionally since 1995 and have never seen such a clear walk through. I'm always looking for teaching materials to share with my team. This is best in class!

I have watched up till 10 minutes as of now but I've learned so much things about Libvert networking that are really not available anywhere . Really man thanks!

This video helped me clarify a lot of the concepts I was muddling through as I build my first home lab! Really appreciated your explanations both in concept & practice!

Apparently, I used this video almost a year ago. I just rediscovered it as I am back to trying to figure out VM networking. This is hands down the best youtube lecture on an IT subject ever! And the accompanying blog - just fantastic. Thanks so much. You are an excellent teacher.

It's a shame that you haven't been able to post more videos on the topics you mention at the beginning. You're an exceptional RU-vidr! You present the topics succinctly, give apt examples and back up everything with solid articles.

Hello, This is the only tutorial that allowed me to create a bridge interface for libvirt/kvm. Just one point, your blog site does not seem operational. A big thank you from a French subscriber!

by far the most sane content about kvm bridge networks.

Great view, exactly what was missing from the existing KVM bridge articles!

The hidden gem...! I am a beginner to all these concepts but still he made me sense to all the things he did in video. All credits to his way of explanation. Thanks Josh. Looking forward for more such vidoes on all the Computer Science topics.

I am so glad I found your channel! You have a natural talent explaining these stuff. Please keep going!

thanks a lot. I've followed yur video interactively and have now to servers with libvirt running on a bridge. This actually a office project where we are making a virtual network for some databases. Again thanks a lot for your knowledge the the way you teach and sahre it. I am waiting for some om kubernetes.

Excellent tone and excellent accompanying post; this is a very high quality video and I’m keen to check out more of your channel! Please keep up the even keel and professional tone with minimal spammy and erratic calls to action. Linux and OS details run deep and there is plenty of good stuff to get into so please please keep it up-bravo!

Thanks a lot, as a newbie, it really help me to understand how does Linux bridge work.

im old Linux guy, but new to VMs this vid is precious thank you

Being able to explain complicated matters in simple and understandable ways shows how much you understand the subject in hand. Excellent content

Thanks a lot! I was beginning to pull my hair out trying to get my bridge to work. I tailed the syslog and noticed my ufw firewall was blocking the DHCP broadcasts, when I was testing the dhclient tool. After a little change to the firewall, the VM was able to get an IP address and could browse the Internet. When in doubt, check the logs (something I don't always do at first).

I came here because his kvm/qemu/libvirt primer is one of the best out there. Great work!

Awesome video. I was scouring the internet for KVM bridge networking and everything I found was missing pieces. Your video was complete and I was able to get it up and running. Thank you!

This is amazing stuff. So straight to the point! The diagrams and manual walkthrough really drew me in. Thank you, man.

Thank you! Through brutal trial-and-error I got an Ansible play using nmcli to accomplish this for a KVM host for its VMs without fully grokking what it was doing (at least, it was through a glass, darkly...). Your video and blog has explained it very clearly.

Extremely awesome video! At first I thought because of the length it wouldn't really be structured and just another video covering one specific case while not explaining the bigger picture, but the like-ratio convinced me to watch it either way, and I absolutely wasn't disappointed. Keep it up!

This is EXACTLY what I was looking for and wonderfully explained. Great! Thanks so much.

Awwwwesome !!, first video on the topic in details and with practical. Big thank You !!

Thanks for your time making these videos and your posts......was wandering down the 'rabbit hole' when I was getting my feet wet with VMs, somehow stumbled upon your posts, and for me, learned a few things, but more importantly, had a bunch of 'AHA!' moments...........the way you wrote them all up/filmed filmed them 'brought it all together' for me; the whole relationship between QEMU/virsh/libvirt, bridged networking (and how to REALLY check to see whats going on with your virtual networks), and everything else in between. Wait for my next review, when I curse your name for making me dabble again with some clusters............lol. But seriously man, thanks! +1 in the 'Time Not Wasted' column!

Great stuff, thank you! Having worked in the corporate "Windows" world for decades, my personal preference has always been Linux. I love your deep-dive into KVM, especially this networking bit, including the accompanying blog. Keep up the good work!

Thank you so much. I was at this two days trying to get a bridged network going on an OMV box with KVM/QEMU installed. I have lost count of how many articles and tutorials I went through without success. I now have a much better understanding thanks to your thorough explanations. My VMs are now visible on the local network, all is good. Top work, thanks again.

This video is awesome! I've learned things that I couldn't find or understand from books. Great job!

Thank you for another great video! Networking in Linux is something I always struggle with and this helped me a lot actually. I think there is not enough quality content on this topic out there, so I am glad you posted this. I had a small problem with DNS at 24:30 tho. When I checked /etc/resolv.conf, nameserver was set to 127.0.0.53, which seems to be set by systemd-resolved on boot. I had to manually change it to my Pi-hole address and everything is working now. Probably more people will have this problem, or at least those who use Ubuntu. (This problem only appears with the manual setup - systemd sets up everything properly. And also, if you manually change /etc/resolv.conf, you are going to loose these changes after reboot.)

Thank you man. It's awesome what you did. I'm looking forward to your new videos.

This is one of the best explainer videos I’ve seen. Concise, clear, and informative. Thank you.

Thanks for sharing your expertise on this complex subject. Your videos are exceptional and easy to follow for the layman. I am a 60-something hobbyist experimenting with Linux servers and networking in my home lab. Your videos remind me of being in a community college class and I am grateful to be able to learn from you. Your blogs have also been a great help in supplementing your videos and make it easier for me to grasp the concepts behind what I am doing. Bravo, stay safe, and continued success on your channel.

Good god I needed this. Been trying to learn the whole “vm everything” tech on my laptop (because it has over 1TB of free storage while my desktop doesn’t, and two GPUs) and I use a VPN that allows me to block all non-VPN traffic, which I obviously do. Anyway, after getting a windows VM running with everything passed through (mostly just to see what had to be done to properly pass, say, the dGPU through) and working, I had gotten pretty annoyed with having to disable the firewall for the VM to reach the internet, along with the fact that the VM was bypassing the wire guard device. A full day of troubleshooting and scanning the blog post vigorously later, I think I understand how the hell the default configuration for the VPN routes packets to the wg device, so I can finally feel comfortable actually following the tutorial. Seemed pleeeeenty detailed so I’m pretty confident it’ll work, as long as I get it connecting to the WG correctly. PS: who the hell writes a rule like “not from all fwmark (whatever it was) lookup (numbered table)” to direct all traffic to that table’s routing, if it doesn’t have the fwmark, and only if it specifies noprefixroute. And how the hell even *do* you label a connection with noprefixroute?

This is a great video to explain, visualize, and setup QEMU VM's networks! Thank you.

Excellent educational video from someone who really understand what a bridge is and how it related to VM instances. Thank you.

2000 subscriber !!! Man you have talent to explain please don't stop what are you doing !!!! I love your work !!! ❤️❤️❤️

Well structured... You are a very good instructor. Cheers,.

Thank you for explaining in a more conceptual manner. Now i understand I've had i set for more than a month, but just didn't connect the VM directly to the bridge interface :D

Very well done video, thank you! Looking forward to more content on your channel. Firewall configuration in relation to bridging is confusing as heck... your video helped me confirm I was actually doing things right, and clued me in that "something else" was up when it didn't work. I finally figured out this was because net.bridge.bridge-nf-call-* kernel parameters for the br_netfilter module were all set to 1, meaning that bridging was processed by my firewall (and getting nowhere). If you have useful rules for bridging though (e.g. you use docker) you *don't* want to blindly turn those off, but rather look for the iptables/netfilter/ebtables solution appropriate to your needs.

This was very informational. Thanks for sharing!

Superb! Thank you very much for this high quality lecture.

You have a talent explaining stuff, bro. For the first time I've understood something connected to networks, bridges and switches 🤯 Well done, thanks a lot!

I was trying to manually create a k8s lab locally and this video demystified so many pieces❤

You're a natural teacher, looking forward to more content.

Best presentation bro ... thanks for the video on VM Networking...

Spent a couple hours on this video, best information ever for setting up a virt bridge. I'm a subscriber now, thank you

Awesome video!! I think this is gonna be my weekend project!!

Excellent tutorial Josh. This helped me troubleshoot a problem I had in my virtual network.

without any doubt, this guy deserves to be rewarded somehow by subscribing, very helpful, very clear, and have a very nice teaching skill. well done Josh :)

Thank you for this video! I was looking on google for so long as to how to do this. The docs are sometimes hard to follow. Thanks for this and the blog post!

Great work. this is exactly what I was looking for. Thank you very much and keep up the great work.

I have built that br0 a hundred times on my hypervisor, but the VM's I build, which use bridge=br0, were never visible on the LAN. This is the first time anybody has ever said that the libvirt default network should be shut down when you launch the VM! I always assumed the libvirt default network was just 'handing off' the networking of the VM's to thew host's network, in some magical way. I am astonished. Thanks so much!

It's simple, understandable. Thanks for making such videos. as we are moving towards container, please make some videos on container/pod n/w as well. Thank you!

Pretty cool stuf indeed and what is new you make it look easy. Thanks

Extremely helpful video. So far, I've tried to understand qemu/kvm/libvirt/whatever so many times and always have been devastated by the official docs and other articles... but not this time. +1000000000

This is amazing, I've been looking for some explanation like this for days. Thank you so much !

Excellent, very clear and fast! Luvit, thanks!

I think perhaps the best way to reason about the nature of the setup is to just call the bridge a virtual switch (which it is). Plugged into this virtual switch are: 1. the physical ethernet cable that uplinks to the physical switch 2. the host machine 3. the vm And since switches are L2 devices, their existence is completely transparent to the L3 IP protocol. All the router/gateway knows is that there are multiple hosts connected to one of its ports; whether it's physical or virtual it simply doesn't care.

Great video, keep it and I'm waiting to see more content

Thanks a lot for this deep dive into VM networking. You're dope dude!

great job! Your explanation is very clear. Thanks a lot!

For someone coming from using Virtualbox on Linux for over 6yrs and recently moving to KVM this video is invaluable, since the shift in "difficulty level" of using KVM, especially from networking standpoint is somewhat of a steep-one. Your video simplifies and explains things, that are not so easy to find or follow from the official docs. Virt-manager has almost no documentation, libvirt documentation isn't easy to follow, and between libvirt and Qemu documentation, for a KVM noob, it is easy to get lost. Subscribed with thanks.

This is an excellent tutorial. Thank you very much.

Very good explanation!... Exactly what I needed to know to make my homelab work as I want to. I just would add (to make this explanation an excelsior one) how DNS resolving services work in NATed networks as computers in my physical network (Hypervisor host included) don't reach virtual machines guests by name and I really deeply HATE using ip numbers to access network resources. Problems were NOT found when I used a bridge on the host as my local DNS had no issues to resolve virtual machine guests IP addresses.

Excellent video, great content. Looking forward to seeing more tutorials, maybe some openvswitch in the near future

Fantastic, learned so much. Thank you.

Found it helpful & easy to follow.thanks

Good stuff! Interesting and fun video. Definitive learned something new today :)

Awesome stuff just when I needed it in my work 🙂!!

Very nice video. And the corresponding website to make it easy to follow along. Helped with the conceptualization of what KVM was doing with the "default" network. The only key difference for me is that I am doing this on a rented server facing the internet, so I can't get DHCP from an external router. I need to preserve the concept of libvirt providing it's own network DHCP and then allow that internal network to bridge out to the WAN through the phyical NIC on the server (I will also be using 2nd NIC like you are).

Great video mate, so easy to follow!

Thank you for sharing your knowledge with us.

Recently decided to convert my home lab from Proxmox over to DIY Arch hypervisor. Your videos have been a game changer. The way you start with bare-bones abstraction and work your way up is amazing for not only knowing WHAT to do, but understanding the underlying machinery. Thank you. It seems like you’ve been inactive on RU-vid for a while, but I hope you’re still educating people in other areas of your life. You’ve got a gift for it.

Dude... Great stuff -- keep it coming.👍

Great great video and I only watched 7 minutes. I hope to find more useful content! Subscribed for sure! Thank you.

Love your tutorial. thank you for this great content.

A superb masterclass! 5 star

Thank for insight, helpful video & thank for your efforts.

Awesome explanation.

Thank you for this video, great quality and content! What the hell, where is the patreon or buy-u-a-beer link? Really I'm very greatful!

Concise explanation. I love how you distill all the network bit into the easy to understand 10 minutes explanation.

Your channel is great man, really hope to see more content on it :)

awesome content! thank you for another great video!

Was looking for exactly this!

this was awesome, thank you!

This is excellent. Gave you a sub/like. Would love to see this extended to static IP's and also have the VM's use a different network address range to the host similar to the way AWS hosts have an internal IP addressing scheme but can also have a public IP address.

awesome indeed. helped me a lot! thank you

Great content man! I learned so much!

Amazing info. Thanks

This is no nonsense guy. Straight to the point. 👍

I've seen lots of videos demonstrating doing it this way but nobody that I can tell has done a video on how to do it using macvtap. Thats the instructions I need. ;)

I found a gem! Thank you so much.

thank you. excellent tutorial.

* * * * * = Totally awesome, this is exactly what i was looking. Simply, Clear, Outstanding!!!

Can you setup the vm network using NetworkManager daemon instead of systemd-networkd ? Thanks so much, you were very thorough, clear, and invigorating (meaning not boring). You truly deserve more subscribers!

Excellent vid amigo.

you've no idea how grateful i am for this video. thank you. sub'd

That was great I understand it very well thank you

Today you are my SUPERHERO!

Very good video. I like it. Very usefull. thanks 😁😁😁 I want to setup a bridge network.

This man is already in the meta verse while I cannot even get internet in my vms