Can a Cisco ASA 5505 Have Two External IP Addresses

Posted on 2009-02-17
Last Modified: 2012-05-06
Hello Experts,

I currently have a small Microsoft SBS network that I want to (1) improve security on (2) install a web server on.  I'm thinking of purchasing a Cisco ASA 5505, and was wondering if it could take care of my routing needs.  I will have two external IP addresses.  One for my SBS server which has my Exchange and one for a seperate web server.  Can the Cisco ASA 5505 do this or am I going to need an actual router?
Question by:ndalmolin_13
    LVL 43

    Accepted Solution

    Yes, the ASA can handle this.  The ASA won't be configured with two IP addresses on its interface but can NAT the second IP to one of the servers.
    LVL 1

    Author Comment

    Is this difficult to set up?  My Cisco knowledge is very limited.
    LVL 43

    Expert Comment

    The ASA has a graphical interface (ASDM) which makes the setup pretty simple so you don't have to know the command line extensively.  You can use the CLI for the initial setup but then use ASDM for further configuration.  Plus, there are plenty of experts here that can assist with the setup/configuration.
    LVL 6

    Expert Comment

      No it shouldn't be hard.  There are tools to make it easy like the Security Device Manaager that give it to you in a gui.
      You should see that your ASA has 2-3 ports on the back that should be like ser 0/1 ser 0/0 and aux.  You can give your serials public IP's and then the Fast Ethernet ports would have the private so you could also do failover loadbalancing if needed.
    LVL 11

    Expert Comment

    if you want to route the 2nd IP address, I believe the APA's are capable of using sub interfaces aswell.

    So, you could:

    int fa0/0
    ip address
    no shutdown
    int fa0/0.1
    ip address
    no shutdown

    Not sure if this is what you want to do; this would require also routing these interfaces separately.


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