Running Cisco IOL Devices in Containerlab

Suresh Vina -

Containerlab v0.58.0 supports running Cisco IOL images, which is something I was very much looking forward to. IOL nodes are an implementation of Cisco IOS-XE that does not run as a full virtual machine. Therefore, the IOL nodes generally consume much less CPU and memory.

Containerlab already has great documentation on how to use Cisco IOL devices, but I'll cover it here as well for any of my readers who are interested. You can check out the official documentation for more info.

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Please note that IOL images are the property of Cisco, and redistribution is not permitted. This guide is intended for educational purposes only.

If you are new to Containerlab, feel free to check out my introductory blog post below.

Containerlab - Creating Network Labs Can’t be Any Easier
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PacketswitchSuresh Vina

If you have Cisco CML (you may need version 2.7 or later), it should include the IOL images. You'll need to use vrnetlab to convert the binary file into a Docker container, which can then be used within Containerlab like any other container/image.

First, I have downloaded these two Cisco IOL files to the Downloads folder. One for L3 and another one for L2.

  • x86_64_crb_linux-adventerprisek9-ms
  • x86_64_crb_linux_l2-adventerprisek9-ms.bin

Next, clone the hellt/vrnetlab repository to your local machine. 

git clone https://github.com/hellt/vrnetlab.git

Then, copy these two images into the vrnetlab/cisco/iol directory and rename them as follows. (Change the version accordingly)

  • x86_64_crb_linux-adventerprisek9-ms to cisco_iol-17.12.01.bin
  • x86_64_crb_linux_l2-adventerprisek9-ms.bin to cisco_iol-l2-17.12.01.bin
vrnetlab/cisco/iol$ ls
cisco_iol-17.12.01.bin  cisco_iol-l2-17.12.01.bin  docker  Makefile  README.md

Finally, run make docker-image command and wait for it to complete. It usually takes a few seconds. Once done, if you run docker images, you should see the two images for IOL.

docker images
REPOSITORY              TAG              IMAGE ID       CREATED             SIZE
vrnetlab/cisco_iol      l2-17.12.01      bbf110969808   7 seconds ago       607MB
vrnetlab/cisco_iol      17.12.01         a5f109e61e9d   13 minutes ago      704MB

Now you can create your lab as usual with Containerlab. One thing to note is that when using IOL-L2, remember to set the type to l2, as shown below (Line #21)

---
name: multicast_01

mgmt:
  network: mgmt
  ipv4-subnet: 192.168.100.0/24

topology:
  nodes:
    iol-1:
      kind: cisco_iol
      image: vrnetlab/cisco_iol:17.12.01
      mgmt-ipv4: 192.168.100.31
    iol-2:
      kind: cisco_iol
      image: vrnetlab/cisco_iol:17.12.01
      mgmt-ipv4: 192.168.100.32
    iol-3:
      kind: cisco_iol
      image: vrnetlab/cisco_iol:l2-17.12.01
      type: l2
      mgmt-ipv4: 192.168.100.40

  links:
    - endpoints: ["iol-1:Ethernet0/1","iol-2:Ethernet0/1"]

Once the nodes are up, you can SSH to them by using the default credentials admin/admin

iol-1#show version 
Cisco IOS Software [Dublin], 
Linux Software (X86_64BI_LINUX-ADVENTERPRISEK9-M), 
Version 17.12.1, RELEASE SOFTWARE (fc5)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2023 by Cisco Systems, Inc.
Compiled Thu 27-Jul-23 22:33 by mcpre