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Changing TCP/UDP Port no.

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  • Changing TCP/UDP Port no.

    when changing Port no.
    - YUP! This is concerned with Security to the n/w
    Suppose i configured HTTP port no. on FIREWALL changing its default port no. 80 to something else as 4040...
    (1)it will block outer side HTTP request to our n/w
    (2) Firewall will translate port no. 80 to 4040 if any request comes from outer side

    if the option 1 is applied then it means that we will tell to related outer sider user the port no.4040 if he requests for HTTP

    if option no. 2 is concerned then it's useless if it translates in between port no.
    then why change if locally port no. if it will response to every outer side HTTP req!!!

    Any assistance you can provide would be greatly appreciated

  • #2
    Re: Changing TCP/UDP Port no.

    Your opt 1 is the way to go, if you want to limit access to the page you're hosting.

    If you don't want the whole internet to be able to see a page you're hosting, then set your firewall to port-forward from 4040 on it's external interface to port 80 on it's internal interface, to your server. Then only tell those who you want to have access to set their web browser to your page/port (i.e. and they're in.

    Make sure your firewall isn't responding to pings from outside to cut down on sniffers finding you. But it all depends on what you want to do, security-wise.
    MSCA (2003/XP), Security+, CCNA

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