Multiple IP Assignments on Cisco ASA 5505

Posted on 2011-04-22
Last Modified: 2012-05-11
I have a client that has a Cisco ASA 5505.  They currently have a /30 assignment from their ISP, which is giving them one public IP.  They have some things that depend on that IP remaining the same, such as a site-to-site VPN and various NAT rules that are in use.

They have new two devices that they are putting inside their network now that need to be accessible from the outside, with each on its own public IP addresses.  We can't just use PAT for these and stick them on different ports on the existing public IP, as whatever is going to connect to them (not sure if it is software or hardware of some kind) will not allow different ports to be specified.

The ISP has given them an additional block of network addresses to accomplish this, a /29 block.  This is a totally separate block from the preexisting /30, with its own default gateway as well.  I need to somehow configure the ASA to use both of these networks.  I can’t just cut over everything that was on the /30 to the /29, as I don’t know who all is relying on that public IP remaining the same.

I can't figure out how to configure the ASA to work with both of these networks at once.  Does anyone have any suggestions?
Question by:NSPOneSource
    LVL 3

    Expert Comment

    buy a second asa5505 :)
    LVL 3

    Assisted Solution

    do you have a sec plus licence?
    LVL 1

    Author Comment

    No sec plus, just base on this device.
    LVL 20

    Accepted Solution

    You need a second device for the new address block. You don't need to change something on the existing one.

    Featured Post

    Looking for New Ways to Advertise?

    Engage with tech pros in our community with native advertising, as a Vendor Expert, and more.

    Join & Write a Comment

    If you have an ASA5510 then this sort of thing would be better handled with a CSC Module, however on an ASA5505 thats not an option, and if you want to throw in a quick solution to stop your staff going to facebook during work time, then this is the…
    Quality of Service (QoS) options are nearly endless when it comes to networks today. This article is merely one example of how it can be handled in a hub-n-spoke design using a 3-tier configuration.
    Excel styles will make formatting consistent and let you apply and change formatting faster. In this tutorial, you'll learn how to use Excel's built-in styles, how to modify styles, and how to create your own. You'll also learn how to use your custo…
    Here's a very brief overview of the methods PRTG Network Monitor ( offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

    733 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    21 Experts available now in Live!

    Get 1:1 Help Now