In this video we explore some deep(ish) networking concepts that pertain to how VMs can communicate with one another! Blog post: octetz.com/doc... Libvirt intro post/vid: octetz.com/doc... Twitter: @joshrosso
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!
This is an AWESOME (all caps) video! I've been a user of virtualization technologies in the data center for a long time and a Linux user my whole career but have never delved into the details of "how does this all hang together?", and this is just the kind of video I needed to get me started: an exposition which goes into concept details alongside the actual configurations, and not simply the usual "these are the commands you need" which as octetz pointed out "might not work on every distribution" and why. I cannot thank you enough for the quality you put out into the world here.
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!
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.
This is the best explanation I have seen of this particular topic I have seen so far. You are a fantastic teacher, and your depth of knowledge is really impressive!
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.
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!
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.
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.)
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!
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.
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!
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.
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 :)
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.
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!
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.
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
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!
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!
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!
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.
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!
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. ;)
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).
AWESOME! Thanks for this great content. Content suggestion: compare network configuration differences on systemd-networkd vs /etc/network/interfaces etc.
Hi josh.these videos on linux virtualization are some of the best i have seen on youtube. You clearly have a talent for teaching computer techology. However your great blog material is not available using link. Can you fix that because although your video material is excellent...having your blog would be even better. Thanks
Excellent explanation/learning. BUT no mention of promiscuous mode setting for some switches. Would that stop VM access? And in the past I have been successful doing similar setups using wicked/openSUSE but I have never gotten one to work bridging with WiFi adapter.
Awesome video, thanks for sharing Josh! I'd love to also read the related blog posts, but your website seems to be down? Are the posts still available somewhere? Thanks!!
can you suggest a couple of books to find what you cover here. i feel like i am cheating by watching and not doing the legwork for myself. thanks again!
@Josh Rosso cool beans, thanks for a good explanation!. One thing I do not understand is, why not put the IP on the hypervisor interface? won't that let the VMs route packets through the bridge?
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.
my head exploded. this material is above my head at this point, but I guess i learned something. I think I want to learn more virsh so that i can use a headless server. I had hoped you'd go through installing a distro using an .iso, allotting RAM and CPU and storage. Maybe that was on your first video. I'll go look.
I'm trying to utilize another static IP addresses from my dedicated server for my VMs. I'm having an issue trying to get bridge setup and adjust my /etc/network/interfaces to not use it on my dedicated machine but allow my VM to use that static ip by bridging it.
capv I see what you did there ;) I love ClusterAPI... Great tutorial for beginners! Unfortunately i think the zooming in and out in your terminal is very distracting. Just leave it at one zoom level. You can zoom in yourself on mobile now so that's not a problem anymore;)
another question, when setting up a bridge br0, and launched the VM, but the VM still not able to access the internet, do I need to set up systemd-networkd service in the VM? I launched a debian VM but systemd-networkd service is not started. And after I started it, I still can not gain ipv4 address, so there is no way to access the internet.
This was really helpful in understanding VM networking. I'm new to it but I learnt a lot from this video. I have two questions; 1. Instead of the private IP you used, can I make use of a public IP /26 precisely? 2. How do I make the IP assignment to the VM static and not dhcp
1: To enable a public `/26` (~64 IPs), you'd first need to acquire a block from your ISP. Typically this is costly and some ISPs won't even offer it. 2: There are a variety of ways to setup static IPs. One that I generally recommend is to actually setup DHCP reservations for hosts based on their MAC addresses. This enables you to set IPs for hosts without worrying about configuration on the host itself, however this can have trade-offs[0]. Otherwise, static IPs can be setup using systemd-networkd[1] among many other options. [0]: serverfault.com/questions/544619/static-ip-vs-dhcp-reservation [1]: wiki.archlinux.org/title/systemd-networkd#Wired_adapter_using_a_static_IP
@@joshrosso Thank you for the assistance. I have a block of IP already and I tried the configuration on systems with the static IP. After restarting systemd-networkd, the bridge was created and linked to the specified interface but the IP assigned was a private IP and not the public IP I specified.
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!
yeah, im going this professionaly from 1985
i was starting learn since 1995 year
This is an AWESOME (all caps) video! I've been a user of virtualization technologies in the data center for a long time and a Linux user my whole career but have never delved into the details of "how does this all hang together?", and this is just the kind of video I needed to get me started: an exposition which goes into concept details alongside the actual configurations, and not simply the usual "these are the commands you need" which as octetz pointed out "might not work on every distribution" and why. I cannot thank you enough for the quality you put out into the world here.
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!
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.
Same. I was here 8 months ago.
This is the best explanation I have seen of this particular topic I have seen so far. You are a fantastic teacher, and your depth of knowledge is really impressive!
I am so glad I found your channel! You have a natural talent explaining these stuff. Please keep going!
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.
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!
This was driving me nuts for like 3 days. Thank you so much for this concise explanation and walkthrough! :)
Being able to explain complicated matters in simple and understandable ways shows how much you understand the subject in hand. Excellent content
Great view, exactly what was missing from the existing KVM bridge articles!
Very grateful for your methodical hands on approach with thorough explanations....
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.
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.)
This is amazing stuff. So straight to the point! The diagrams and manual walkthrough really drew me in. Thank you, man.
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!
I came here because his kvm/qemu/libvirt primer is one of the best out there. Great work!
This is EXACTLY what I was looking for and wonderfully explained. Great! Thanks so much.
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.
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!
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.
This video is awesome! I've learned things that I couldn't find or understand from books. Great job!
Thanks a lot, as a newbie, it really help me to understand how does Linux bridge work.
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 :)
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.
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 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!
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 educational video from someone who really understand what a bridge is and how it related to VM instances. Thank you.
You're a natural teacher, looking forward to more content.
im old Linux guy, but new to VMs
this vid is precious
thank you
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
Hey Josh! Well done video and well explained! Thank you for the content!
Thanks a lot for this deep dive into VM networking. You're dope dude!
I was trying to manually create a k8s lab locally and this video demystified so many pieces❤
Thanks Josh. It is a very didactical explanation, and a great contribution to the community. I have suscribed to your channel
2000 subscriber !!! Man you have talent to explain please don't stop what are you doing !!!! I love your work !!! ❤️❤️❤️
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!
Concise explanation. I love how you distill all the network bit into the easy to understand 10 minutes explanation.
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!
Well structured... You are a very good instructor. Cheers,.
Awwwwesome !!, first video on the topic in details and with practical. Big thank You !!
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!
This is amazing, I've been looking for some explanation like this for days. Thank you so much !
Great work. this is exactly what I was looking for. Thank you very much and keep up the great work.
Pretty cool stuf indeed and what is new you make it look easy. 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.
Awesome video!! I think this is gonna be my weekend project!!
Best presentation bro ... thanks for the video on VM Networking...
Excellent tutorial Josh. This helped me troubleshoot a problem I had in my virtual network.
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!
This man is already in the meta verse while I cannot even get internet in my vms
Great great video and I only watched 7 minutes. I hope to find more useful content! Subscribed for sure! Thank you.
Such a great presentation.
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. ;)
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).
* * * * * = Totally awesome, this is exactly what i was looking. Simply, Clear, Outstanding!!!
you've no idea how grateful i am for this video. thank you. sub'd
Awesome stuff just when I needed it in my work 🙂!!
Dude... Great stuff -- keep it coming.👍
EXTREMELY useful in the context of AWS networking! Do you offer a course?
Excellent, very clear and fast! Luvit, thanks!
Hello, very clear. But, how to set it on a remote system? Naturally when I bring down ethernet connection I am out. (noob here)
Thank you in advance.
Use VNC to login the remote system.
Fantastic, learned so much. Thank you.
Was looking for exactly this!
AWESOME! Thanks for this great content. Content suggestion: compare network configuration differences on systemd-networkd vs /etc/network/interfaces etc.
Yeah that's an excellent idea. Perhaps a video on "Linux IP Initialization" approaches is in order?
@@joshrosso absolutely!
Hi josh.these videos on linux virtualization are some of the best i have seen on youtube. You clearly have a talent for teaching computer techology. However your great blog material is not available using link. Can you fix that because although your video material is excellent...having your blog would be even better. Thanks
Your Blog post site is down. Any other link?
This was very informational. Thanks for sharing!
Excellent explanation/learning. BUT no mention of promiscuous mode setting for some switches. Would that stop VM access? And in the past I have been successful doing similar setups using wicked/openSUSE but I have never gotten one to work bridging with WiFi adapter.
Awesome video, thanks for sharing Josh! I'd love to also read the related blog posts, but your website seems to be down? Are the posts still available somewhere? Thanks!!
can you suggest a couple of books to find what you cover here. i feel like i am cheating by watching and not doing the legwork for myself. thanks again!
Found it helpful & easy to follow.thanks
@Josh Rosso cool beans, thanks for a good explanation!. One thing I do not understand is, why not put the IP on the hypervisor interface? won't that let the VMs route packets through the bridge?
Good stuff! Interesting and fun video. Definitive learned something new today :)
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.
Love your tutorial. thank you for this great content.
Thank you for the video! It is amazing but the blog posts seem to be down. Hope it gets fixed soon!
I found a gem!
Thank you so much.
That's great tutorial. How do you bridge vm when you also have a bond (bonding load balancing) interface on the two physical interfaces?
Excellent video, great content. Looking forward to seeing more tutorials, maybe some openvswitch in the near future
this was awesome, thank you!
Awesome explanation.
my head exploded. this material is above my head at this point, but I guess i learned something. I think I want to learn more virsh so that i can use a headless server. I had hoped you'd go through installing a distro using an .iso, allotting RAM and CPU and storage. Maybe that was on your first video. I'll go look.
Great video thanks, question if you have a few seconds. Why couldn't the LibVirt bridge be used? 'virbr0'?
Your channel is great man, really hope to see more content on it :)
Thank you for sharing your knowledge with us.
I'm trying to utilize another static IP addresses from my dedicated server for my VMs. I'm having an issue trying to get bridge setup and adjust my /etc/network/interfaces to not use it on my dedicated machine but allow my VM to use that static ip by bridging it.
Good stuff! Do you have a video that combines this with adding a vlan tag on a bridge?
looking forward to your new tutorial. peace
capv I see what you did there ;) I love ClusterAPI... Great tutorial for beginners! Unfortunately i think the zooming in and out in your terminal is very distracting. Just leave it at one zoom level. You can zoom in yourself on mobile now so that's not a problem anymore;)
Thanks for great video. Can you please check the Blog post link which you have mentioned in description... not able to access.
Where are your next videos? Content is sooo good, you shouldn't stop making these. I think your videos are most informative from whinch i found on YT.
This is such a great tutorial. Sadly, though, I can't reach your website. Is it down?!
Very good video. I like it. Very usefull. thanks 😁😁😁 I want to setup a bridge network.
awesome indeed. helped me a lot! thank you
VMware workstation can have a bridge and NAT configuration used on the same physical interface for different VM's. Is that possible with libvirt?
Hello josh I’ve created the bridge interface and the network works well in my main machine. But my VMs didn’t obtain even an IP address.
another question, when setting up a bridge br0, and launched the VM, but the VM still not able to access the internet, do I need to set up systemd-networkd service in the VM? I launched a debian VM but systemd-networkd service is not started. And after I started it, I still can not gain ipv4 address, so there is no way to access the internet.
This was really helpful in understanding VM networking. I'm new to it but I learnt a lot from this video. I have two questions; 1. Instead of the private IP you used, can I make use of a public IP /26 precisely? 2. How do I make the IP assignment to the VM static and not dhcp
1: To enable a public `/26` (~64 IPs), you'd first need to acquire a block from your ISP. Typically this is costly and some ISPs won't even offer it.
2: There are a variety of ways to setup static IPs. One that I generally recommend is to actually setup DHCP reservations for hosts based on their MAC addresses. This enables you to set IPs for hosts without worrying about configuration on the host itself, however this can have trade-offs[0]. Otherwise, static IPs can be setup using systemd-networkd[1] among many other options.
[0]: serverfault.com/questions/544619/static-ip-vs-dhcp-reservation
[1]: wiki.archlinux.org/title/systemd-networkd#Wired_adapter_using_a_static_IP
@@joshrosso Thank you for the assistance. I have a block of IP already and I tried the configuration on systems with the static IP. After restarting systemd-networkd, the bridge was created and linked to the specified interface but the IP assigned was a private IP and not the public IP I specified.
I’ve resolved it. Thank you so much 🙏