OpenWrt Virtual Testbed?

For Developers
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I tried the docker image openwrtorg/rootfs in GNS3. It seems to work, but don't forget to add /etc/config (or maybe /etc) to the directories that are saved by GNS3.

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I've not used GNS3 in a long, long time. I remember being able to run Cisco cIOS images on it though. It's a great sandbox. Wonder if a How-To on setting up a testbed like that would be worth someone doing.. peer @mikma :laughing: :blush: :+1:

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Thanks @Grommish and @mikma. It looks like people would prefer gns3. I have no idea of it, but if I get it running, I think I will upload my project somewhere. :slight_smile:

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Do I have to add for each GNS3 OpenWrt-Router Instance a new virtualbox VM?

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If you use the openwrt appliance template that's included in gns3 then it will use one vm for each instance I assume.

But gns3 slso supports docker instances. If you use a Linux host then you don't need any vm at all. On other systems you need one vm to run docker. The openwrtorg/rootfs image can be used as a router directly, but you may want to use it as a base for your own Dockerfile if you need more packages.

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@vgaetera You mean using libvirt to start VMs and then use netem simulate traffic on the virtual interfaces?

@mikma Wow, just imported one docker instance and it directly works! :slight_smile: I want to compile own images with special kernel falgs and so on. That is why I need something I can import myself. But this docker stuff seems awesome!!! :smiley:

Edit: Works means, I was able to start telnet session via gns3... xD

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@mikma That docker stuff is awesome!!! :smiley: That directly works with latest https://hub.docker.com/r/openwrtorg/rootfs

Offtopic:

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Docker containers use the kernel running on the host. It doesn't use a Kernel from OpenWrt.

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Even better, than I do not have any issues since my host kernel already ships with the needed modules (I believe). :smiley:

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@mikma
Could u describe the limitations of using docker with gns3?
I don't have full control over my network stack, or?

root@d6c348965795:/proc/sys/net/ipv6/conf/all# echo "1" > seg6_enabled 
/bin/ash: can't create seg6_enabled: Read-only file system

If I do the same in GNS3 it works. But I have no ip-full right now installed, to test if it will work.

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You should probably use full virtualization, because it's problematic to achieve the proper level of isolation required for testing of kernel specific features with just OS-level virtualization.
Container-based virtualization is not for testing OS, but for deploying/testing applications/software.

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Containers can be isolated from the docker host with user namespaces. Is that enough? (It's used by default in for example lxd, but not in docker.)

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I have now a running virtualbox setup, too.
You can just create a virtuablox x86 system and do this "linked vm".
Further do the settings

  • Start VM in headless mode
  • Allow GNS3 to juse any configured VirtualBox adapter
  • Telnet Console

I have to read more documentation about user namespaces and stuff like this.

Thank you!

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There is no way of simulate a wireless link in gns3, or?

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what exactly do you need to simulate?

you can do latencies/loss via netem... and there is this - scroll down to add some shaping but with 2.5 stuff like batman... things are difficult... vm pci passthrough... a few cheap devices are alot easier...

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I would like to build a wireless network like we have in our Wireless Community (Freifunk Berlin). I want to test new IPv6 features and their impact on our wireless links.

There is also mininet.org, but I think it does not give me a full featured OpenWrt node.

I saw that I can add to a link

  • Frequency Drop Rate
  • Packet Loss Rate
  • Delay/Jitter
  • And BPF Filter

Not sure, if I can maybe measure a link stats and just use them as simulation input for gns3. But I think even other simulation tools have issues with virtual vs real-world deployments.

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Okay GNS3 is not working? Basic ICMP is working. :wink:
I tried to build an iperf connection and it can't connect.

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It works for me anyway. When connecting two openwrt containers via a switch in GNS3 I get 1.15 Gbits/sec. When connecting the wan port on one container to the lan on the other I get 3.18 Gbits/sec. I also tried OpenvSwitch but only got 158 Mbits/sec.

BTW the Cloud device seems very slow, but the NAT device is usable if you need Internet access (package download).

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What. :open_mouth: Okay, I will try again!!! :smiley: Maybe I did something wrong. :sweat_smile: