Running ASDM and WebVPN on the same interface

Introduction

So you are thinking of running ASDM and WebVPN on the same interface? This is quite a rare configuration for the simple reason that ASDM is a management tool and WebVPN is usually enabled on the outside interface and best practice would dictate using an internal or even dedicated management interface to allow ASDM\CLI connections to. However, in a lab environment, this isn’t such an issue. In fact, in my labs, the machine I manage the ASA from is also the machine I test VPN connectivity from so this is a requirement for me.

Running ASDM and WebVPN on same interface

You basically have two options. You can change the port that ASDM runs on, or change the port that WebVPN runs on. As stated, this is mostly seen in a non-production environment so it probably doesn’t matter too much which way you do it but if for any reason you had to use this configuration in production, you would probably want to change the ASDM port so your remote users don’t have to worry about changing ports.

Both options are very simple to implement. To change the ASDM port, you enter a modified version of the command you enter to enable ASDM:

This changes the ASDM port to 4343. As stated, missing out ‘4343’ still enables ASDM but on the default port of 443.

To change the WebVPN port only requires an extra line:

Of course, both services can be run on the same port if required, but you need to know the URL to access ASDM. (The WebVPN URL is the default and so will load with just the IP address\hostname). The ASDM URL at time of writing on software version 9.1(2) is:

https://ipaddress/admin/public/index.html

Once you have downloaded and installed the ASDM launcher, you again don’t need to worry about having different ports as the launcher itself connects to the correct URL automatically.

Summary

There may not be many situations in which you would consider running ASDM and WebVPN on the same interface but it’s good to know it can be done from both a port and URL point of view.

Till the next time.

Please let me know your thoughts!