When it comes to clarity on tricky networking topics, you occupy an isolated namespace of your own. Nice video once again :)

It was a pure joy to watch these videos. Very well explained. Thank you!

This was really well done. Thanks for producing it.

Thanks David for explaining the complex topics in very understandable manner. Makes learning new technology easier.

As always, your videos are good. Keep educating us. Thanks.

Awesome info David ....simple session but covers in-depth technical .Thank you for sharing your knowledge ... :) .

Thank you. This still a good video since 2015 ❤

man oh man, I can't express how helpful this video for me. Pls continue to do more topics on networking!!!

@sandeep Thanks for the detailed feedback! Really helps to hear what works. Just to show there is more than one way really. Also IIRC, that is how OpenStack does it (away from my lab atm, have to double check ;-) )

Very helpful and simplified, as usual. Thanks, David.

2021. This still is a huge GEM! Super valuable content!!! Thank you for making and sharing this!!!

Very nice. Thanks for putting this concise and informative video together. I will definitely be checking out your other videos!

Excellent lecture. Exactly the info that I needed. Thank you very much!

Awesome David ... Thank you for sharing your knowledge ... :)

Thank you David. I am preparing the COA exam, you're videos are simply invaluables

Awesome tutorial on network namespaces. Would love more networking tutorials like this

Hands down one of the best presentations I've ever seen, easy to follow, just the right pace, focused on topic start-to-end. I wish I had come across your channel earlier..

You are REALLY GOOD and you make these concepts so easy to understand. Can't thank you enough.

It's David Mahler's ability to explain difficult concepts in a highly clear and practical manner. A semester or two worth of classes in under 30 minutes. The way the information is presented helps me retain that information. This is priceless. Thank you.

Nice video David, watched a couple of your videos, incremental explanation helps building up the concept. Cheers!👍🏻

I can't thank you enough :) You are a gem of a tutor :) Keep Educating us :)

This video deserves a lot of clap. The best one I have came across. Brilliantly explained.

What can I say - your videos are brain fodder for us networking types. Awesome... just awesome!

Awesome!!!!. Thanks for making these videos. They are very helpful. Please do keep making these videos/sessions.

Thank you David for this video. Again a very nice video, which gives a good overview how Linux namespaces can be used in practice :-)

You are the true teacher of my networking knowledge. I wasted money on uni classes..

this is very sharp and clean. thanks for sharing !

I wish to have seen this video earlier . Thank you so much for easy to understand and detailed description :)

An awesome presentation & explanation . Thanks for this video :)

Simply super. I Love your videos.

Helped me getting my virtual network finally running without any mutual interference. Thanks David!

very clear and concise explanation, good stuff

What a nice tutorial, now I understand the Nuage Network much better on those OVS and network namespaces!

You helped me sooo much! I absolutely love your videos!

Thank you so much for the excellent tutorial about netns.

Always clear, precise and concrete explanations as usual, David. This video was very useful. I like the incremental approach you take for explaining stuffs in neat organized way. Hats off to your efforts for clarity and precision. Cheers and You ROCK! I have one question. Why is that you connected DHCP namespaces to internal ports of OVS and not through VETH pairs (unlike Red/Green host namespace) ?

I am going thorough Red hat open stack administrator course where i did not understand concept of NS clear, but after watching your video i can say now i have more clarity , you have provided detailed knowledgeable which cleared all my doubts . you are doing marvelous job , a Big thank you .

thanks for the crystal clear explanation!

Great stuff! Thank you for putting this together. I wish you had added a section about connecting our 2 networks to the internet and not just keep them isolated but this is already great!

Nice explanation !!! Thanks for the good tutorial

thanks for great video. a lot of interesting information about network namespaces in a short time. Actually demo is easy to follow in your terminal.

David, thanks a lot for your video. The best way to explain something is to show how it works on a real system

short and crisp! Thank you...

very good presentation thx a lot David

David Sir your lecture is too good. ..thanks sir. ..God bless you. .. pls make more video

Awesome video..Thanks a lot for sharing the knowledge.

This is so good... wish I had seen this years ago when starting my network-programming related job 🤣

great. I really like the way you presented!

very nice presentation!

The presentation is really good....!

This is excellent tutorial! Thanks!

David Mahler is a really great guy

Really helpful Sir. Thank you very much.

Great explanation!

Simply brillant!

Checking in in 2020, and gotta say that video is super.

wow nicely explained everything !! thanks

I wish I could thumbs this up twice! Bravo!

Thanks David this is so greate.

Nice explanation...

Thanks a lot. It made lot of things clear to me. I have one question. Do we need OVS to create the bridge or can we use the brctl to create the bridge ?

Thanks a lot for your great videos.

This video is so much more than just linux namespaces.

Great (y) efforts appreciated

Great video! I learnt a lot

Fantastic!Thank you.

Great video!

Thanks, That was helpful

Awesome, good job. Thanks.

wow amazing. .thank you sir

Great video David. Very impressed with all your content so far, keep up the good work :-) Workaround for tap interface problem on later versions of OVS ---------------------------------------------------------------------------------------------------- Like others I've had issues with the tap interface in a later version of OVS. Simply adding the tap interface manually doesn't seem to connect it to the vswitch when you make it an internal interface, and the tap interface never comes up (NO_CARRIER) after being fully configured and moved into the dhcp-r namespace. I have a workaround, but its a little odd. Either there's a bug somewhere, or my understanding of OVS/tap interfaces is even more limited than I thought... Anyway, this works for some reason: 1) In the root namespace "ip tuntap add mode tap tap-r" (creates a tap interface) 2) ovs-vsctl add-port OVS1 tap-r (adds it to the vswitch) 3) ip link set tap-r netns dhcp-r (move the tap interface to the dhcp-r namespace, but *before changing the interface type / port tag*) Now things get weird... 4) ovs-vsctl set interface tap-r type=internal (sets the tap-r interface to internal *but actually creates a new tap-r interface in the root namespace.* Since there's a "tap-r" already listed OVS doesn't generate an error. However, this tap-r is actually connected and can be brought up later) 5) ovs-vsctl set port tap-r tag=100 6) ip netns exec dhcp-r ip tuntap del mode tap tap-r (delete the original tap interface that we moved to dhcp-r) 7) ip link set tap-r netns dhcp-r (move the new, connected tap-r to the dhcp-r namespace) 8) continue with the rest of the config (ie bringing the interfaces up, dnsmasq config and enabling the red namespace dhclient) The process can be repeated for the tap-g interface and dhcp-g namespace. Not sure what's going on here really, particularly why a new tap interface is created when you set the interface type to internal after moving it to a different namespace... but after a lot of trial and error this is the only way I got the tap interface to come up with OVS version 2.5.2 and Ubuntu 16.04.02.

Simply superb!!l

Good video, thanks. Would be even cooler to see how the kernel info changes inside.

Really helpful video. thanks a ton !!!!!!!!!!!!!!!!!

appreciated

very good work thank you

wowowowow........awsome ...i love itttt , please post more on openstack neutron

Awesome !! Thank you :)

great stuff thumps up

I love your videos. What tool you use to record those videos? Thanks

Amazing! thanks! What's up with the audio when you were showing the dhcp ps ids?

Awesome !!! Thks a lot

Nice, so the built in linux namespace has dhcp component which is not part of openswitch?

Thank you for your video. could you please help with this question: I encountered with a problem with the simplest lab: I created three cirros instance​s in openstack and through CLI I created 2 namespaces Red and Green. I chosen ovs's qvo interfaces of two cirros VM and apply them to RED namespace (I found them using Nova interface-list instance_id). I applied IP address 192.168.1.1 and .2 respectively on those VMs, but they cannot ping each other. I see only ARP request without ARP reply. How do you think what's the problem in such behavior? Why two instances being in the same namespace cannot reach each other?

helpful video

Wonderful

Beautiful! Thanks! Probably, I am not the first one, who is asking about your output highlighting trick. How do you turn some output in SecureCRT to red and other lines to green? I know, SecureCRT can highlight, but you are doing this on click (like in PowerPoint). How?? :-)

How creation of a new network name space different from running lxc-create command?

How come you could move the tap ports into the network namespace while you had to use a veth pair for the other ports ? Could the eth0-r/g ports be connected to their respective namespaces without a veth pair ? I guess it is a feature of internal ports, but what are the differences ?

For assigning dynamic ip addresses to 2 clients (red and green) you created two DHCP processes in isolated namespaces, my question is why didn't you created two DHCP processes inside each of isolated client? why you created outside the clients?

Awesome explanation 👏🏻 I have a doubt...when I try to ping green(vlan 200) from red(vlan100), will it ping or not? If not..how to connect two vlans?

please share open vSwitch installation video(latest version)

when I type ip netns exec green dhclient eth0-g, there show dhclient is alreading running - exiting. I do this experiment step by step. Is there somebody has any ideas?

Is it possible to run the ovswitch in a separate namespace as well?

Hi I got the following error root@mininet-vm:/home/mininet# ovs-vsctl add-port OVS1 tap-r ovs-vsctl: Error detected while setting up 'tap-r'. See ovs-vswitchd log for details. Any ideas?

could you please tie in the vxlan aspect with this namespaces ?

Looks very similar to vrf lite on Cisco routers

I still cannot get the difference between tap and veth interfaces in their usefulness. Originally, I thought that OVS could not span several namespaces, so one had to use veth in order to have one side in the namespace and the other side in the root namespace part of the OVS bridge. But that also seems to be a common use case to have a tap interface in a namespace and to make it a port of a root namespace's OVS bridge. The conclusion would then be that OVS bridges can span namespaces. But what would be the real difference between tap and veth ? What are their specific use cases ? Or things you can/cannot do with each of them ?

​ @David Mahler Why don't you upload new videos, been waiting for quite some time now ?

I am unable to find your video of DVR