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GNS3 - Configure ASA with ASDM

GNS3 - Configure ASA with ASDM

Warning: Doesn't work with newer ASAv versions, for example v9.12 from CML 2

Update Nov 1, 2017: David Bombal shows this method in his videos "GNS3, Cisco ASA and ASDM: Configure VIRL ASAv firewall with GNS3 and ASDM" Part 4 and Part 5.

David Bombal made a very nice video series: GNS3, Cisco ASA and ASDM: Configure VIRL ASAv firewall with GNS3 and ASDM He uses a Windows VM as a client, where here installed Java. One drawback is, that the Java installation has to be re-done on every new project. Furthermore the license of the Windows VM is time limited. When it expires, you have to delete the VM from the project and insert a fresh one.

Instead I'm using Java in a docker container for ASDM. I've added Java to my webterm docker image and published it as ehlers/web_java. It contains the Firefox web browser, Java and Java web start. Please note, that Firefox has disabled the Java plugin, so this is not included in this image.

To import it into GNS3 open the preferences, select the Docker / Docker Containers section and click on "New".

New Appliance Template

The "New Docker VM template" wizard will start and it asks a couple of questions:

  • Server type: Run this Docker VM on the GNS3 VM
  • Docker image: Select "New Image" and enter "ehlers/web_java" as the image name.
  • Name: Give the VM a name, e.g. web_java
  • Adapters: Stick with the default value of 1
  • Start command: Leave it empty
  • Console type: Change it to "vnc"
  • Environment: Leave it empty, then finish the wizard.

Now the Docker VM preferences window will show up. You have the option to edit the just created template, for example change the symbol. When you're done, leave the preferences with "OK".

Like in David's video create a new project:
ASA Project

On the first time the web_java VM is added, it will be downloaded from the internet, about 200 MB. So depending on your internet access, it may take a while. Then configure a static IP address (here, netmask for the web_java-1 VM (right-click / Edit config). Now start everything up. The ASAv will reboot after the initial boot, that's normal.

The ASAv needs an initial configuration, mainly an IP address on the inside interface, a username/password for management access and an enabled http server.

All that is shown in David's second video of the GNS3, Cisco ASA and ASDM video series starting at 5:38.

ciscoasa# configure terminal
ciscoasa(config)# interface GigabitEthernet0/0
ciscoasa(config-if)# nameif inside
INFO: Security level for "inside" set to 100 by default.
ciscoasa(config-if)# ip address
ciscoasa(config-if)# no shutdown
ciscoasa(config-if)# exit
ciscoasa(config)# username cisco password cisco privilege 15
ciscoasa(config)# http server enable
ciscoasa(config)# http inside
ciscoasa(config)# end
ciscoasa# wr

On the web_java VM we can start the web browser (click on the Start button and select Applications / Mozilla Firefox). Then open the web site https://<ASA-IP>/, in our case But the ASA page doesn't recognize the already installed Java web start, it allows only a new installation of Java. So that's a dead end.

Searching the internet gives the solution, use javaws https://<ASA-IP>/admin/public/asdm.jnlp in a terminal window. While that works, it's a little bit cumbersome. Therefore I've added a Cisco ASDM launcher, integrated in the applications menu. Just put in the ASA IP address and the ASDM starts. The web browser doesn't need to be open for ASDM.

ASDM Launcher

Cisco ASDM

Now you can continue following David's videos, starting with the second one at 10:34.

Update Nov 6, 2017:

For running ASDM make the following changes in the java configuration:
Edit /etc/java-8-openjdk/security/ and remove MD5 in jdk.jar.disabledAlgorithms from the list of disabled code signing algorithms.

In previous versions of "ehlers/web_java" the /etc/java-8-openjdk directory was not persistent, so these changes won't stick. This has been changed.

To update "ehlers/web_java" open a GNS3 project, that doesn't use the web_java VM. Then start a shell in the GNS3 VM and remove the old appliance with docker rmi ehlers/web_java, afterwards load the new appliance with docker pull ehlers/web_java.