PIX 525: Prevent internal clients 'bypassing proxy'...

Discussion in 'Cisco' started by Martin, Jan 24, 2007.

  1. Martin

    Martin Guest


    I'm looking for some advice on the following problem:

    Our PIX 525's inside IP address can be added as a default gateway to
    Windows XP clients, so they can in effect, turn off their Internet
    Explorer proxy settings and enjoy a straight-out Internet connection.

    I want to exclude clients in the DHCP range from being able to do this,
    whilst still allowing servers in the rest of the scope to use the
    straight-out Internet connection. We also need to make sure we're not
    barring clients in the DHCP range from accessing the DMZ.

    The inside IP of the PIX is

    The DHCP range of the clients is -
    Servers start at (

    The DMZ range is

    I was hoping to do this with access-lists, but my initial attempts
    would block clients access to the DMZ also. I was wondering if somebody
    might be able to point me in the right direction with this?

    Would be very appreciative of any advice.

    Martin, Jan 24, 2007
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  2. A simple example:

    access-list in2out permit ip
    access-list in2out deny ip any
    access-list in2out permit ip any
    access-group in2out in interface inside
    Jyri Korhonen, Jan 24, 2007
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  3. Martin

    Martin Guest

    Thanks for that, very useful! I was half-way there but was missing the
    point with the permit/deny structure. I've got it working now, and I
    understand where I went wrong.

    Thanks again.
    Martin, Jan 25, 2007
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