mgmt interface with c8000v

[nagraj-kulkarni]

Hi, having hard time getting the connectivity from cisco 8000v to external world. Understand that the mgmt interface i.e first interface , gets qemu dhcp 10.x.x.x and it gets discovered by external routers etc. But i am unable to get the external reachability from the 8000v router itself, tried using the mgmt,addressing schemes in topology/static routes but not helping. How do get it to ping say 8.8.8.8 from the router ? appreciate any help :)

[ipspace]

The management interface (the first Ethernet interface) of Cisco 8000v (and most other devices) is in the management VRF. It should get the IP address from the libvirt DHCP server and it should be in the 192.168.121.0/24 range. To reach the outside world through the management VRF, you have to use the VRF version of the commands (ping vrf or similar)

You can also connect one of the data-plane interfaces to the outside world. See https://netlab.tools/labs/libvirt/#connecting-to-the-outside-world for details (assuming you're using libvirt because you mentioned Qemu)

[nagraj-kulkarni]

Hello, i am using the clab provider and the first interface is getting ip in the subnet 10.0.0.x from qemu dhcp. There is no vrf configured.
I used "addressing/mgmt" etc in the topology file so that it gets the first interface ip from these subnets ( 192.x). netlab status shows the managment ip as 192.x network, but the show running-config in the router does not show any interface having ip in 192.x network,so i believe clab is doing a magic in the underlying bridge, to get reachaibility to router. So in bried, I can do ssh to the router using 192.x, but no interface has ip configured in 192.x ( as per show running), ping from router to external machine (where i am running netlab) does not work, i can not give the default route as 192.x.x.1 in the router as this network is unknown :)

[ssasso]

When using containerlab, with the vrnetlab containers, a sort of 1:1 NAT is performed in userspace by qemu.

You will find an interface with 10.0.0.something, and the default gateway for this is 10.0.0.2

[ipspace]

Ah, vrnetlab. I never understood why someone would use that when there's a perfectly fine way to build virtual machine Vagrant boxes without containers. The convoluted networking they had to do to get things working led me to write this in https://netlab.tools/labs/clab/#using-vrnetlab-containers

vrnetlab is an independent open-source project. If it fails to produce a working container image (example), please contact them.

Anyway, vrnetlab got much better after @hellt forked it. At the very minimum, you should use the latest vrnetlab code from https:/hellt/vrnetlab/ to build the container. For example, https:/hellt/vrnetlab/tree/master/c8000v/docker puts the management interface into a VRF and configures the default route for the management VRF.

[hellt]

It would be assigned by container runtime in this case. Meaning you don't have to statically type it in, but you could assign it statically as well

From the node config perspective this would be a static configuration of the mgmt IP

[nagraj-kulkarni]

@ipspace @ssasso is there a way to create vagrant box without bringing down other labs. I have few labs setup and dont want to disturb them. Getting below error with netlab libvirt package csr disk-image:

netlab cannot create a Vagrant box while there are running labs. Inspect the
status of your lab instances with "netlab status" and stop them with
"netlab down" or "netlab status cleanup --all"

[ipspace]

Unfortunately not. Keep working with the setup you have right now, and build that box once you have to shutdown or reload the server.

[ssasso]

Unfortunately not. Keep working with the setup you have right now, and build that box once you have to shutdown or reload the server.

Or create a virtual machine with nested virtualization capabilities just to build the Vagrant box ;)

(even on some public cloud, most probably it should take less than an hour to build the vagrant box, so in theory the cost should be affordable)

[nagraj-kulkarni]

ok Thank you

[ipspace]

Anyway, it looks like I didn't stress enough the importance of using the (latest version of) @hellt fork of vrnetlab to build the container images, so I (hopefully) fixed the documentation: 20991a5

[nagraj-kulkarni]

Thanks for the quick responses :) for now, i pointed the default gw as suggested by Steffano and it helped. i was in such an awful situation :) will try with vrnetlab fork..Thanks again..

[ipspace]

Here's another idea to build that Vagrant box:

• Start a ubuntu:22.04 container (making sure to map the current directory or some such into it)
• Connect to the container, run the netlab / ubuntu / libvirt installation procedure
• Build the Vagrant box within the container
• Ensure the box-building artifacts are in the host directory mapped into the container (and thus accessible from your server)
• Install Vagrant box on your server with vagrant box add json-file command

[nagraj-kulkarni]

Thanks @ipspace , able to create a box in this fashion, But when i bring the lab up, getting lot of errors !!

`┌──────────────────────────────────────────────────────────────────────────────────┐
│ CHECKING virtualization provider installation │
└──────────────────────────────────────────────────────────────────────────────────┘
[SUCCESS] libvirt installed and working correctly

┌──────────────────────────────────────────────────────────────────────────────────┐
│ STARTING libvirt nodes │
└──────────────────────────────────────────────────────────────────────────────────┘
[CREATED] creating libvirt management network nl_mgmt_12
provider libvirt: executing vagrant up --provider libvirt
Bringing machine 'leaf1' up with 'libvirt' provider...
Bringing machine 'leaf2' up with 'libvirt' provider...
Bringing machine 'spine1' up with 'libvirt' provider...
Bringing machine 'host1' up with 'libvirt' provider...
Bringing machine 'host2' up with 'libvirt' provider...
==> leaf1: An error occurred. The error will be shown after all tasks complete.
==> spine1: An error occurred. The error will be shown after all tasks complete.
==> host1: An error occurred. The error will be shown after all tasks complete.
==> leaf2: An error occurred. The error will be shown after all tasks complete.
==> host2: An error occurred. The error will be shown after all tasks complete.
An error occurred while executing multiple actions in parallel.
Any errors that occurred are shown below.

An error occurred while executing the action on the 'leaf1'
machine. Please handle this error then try again:

There are errors in the configuration of this machine. Please fix
the following errors and try again:

vm:

• The following settings shouldn't exist: allow_fstab_modification, allow_hosts_modification

Libvirt Provider:

• The following settings shouldn't exist: qemu_use_session

An error occurred while executing the action on the 'leaf2'
machine. Please handle this error then try again:

There are errors in the configuration of this machine. Please fix
the following errors and try again:

vm:

• The following settings shouldn't exist: allow_fstab_modification, allow_hosts_modification

Libvirt Provider:

• The following settings shouldn't exist: qemu_use_session

An error occurred while executing the action on the 'spine1'
machine. Please handle this error then try again:

There are errors in the configuration of this machine. Please fix
the following errors and try again:

vm:

• The following settings shouldn't exist: allow_fstab_modification, allow_hosts_modification

Libvirt Provider:

• The following settings shouldn't exist: qemu_use_session
  `

[ipspace]

This is unusual. What version of Vagrant and vagrant-libvirt provider are you using? You can display them with vagrant --version and vagrant plugin list

[nagraj-kulkarni]

root@219e261f47d8:/workspace# vagrant --version
Vagrant 2.4.0
root@219e261f47d8:/workspace# vagrant plugin list
vagrant-libvirt (0.12.2, global)

• Version Constraint: > 0

[ipspace]

I have almost the same version and never encountered similar errors. The parameters are also perfectly valid according to Vagrant documentation https://developer.hashicorp.com/vagrant/docs/vagrantfile/machine_settings

I have no idea what's going on.