Nat, Nat Overload & PAT? Please help!!

ralbertos21ralbertos21 Posts: 27Member ■□□□□□□□□□
I understand that NAT enables you to use a private IP address from a LAN and translates an IP address into a public one when accessing the internet...

I am still confused on what the purpose of NAT Overload means.. does that convert many LAN IP addresses into one Public IP address so it can be usable on the Internet?

PAT??? I have no clue what this is ...

How did you all learn
Inside local/Outside local
Inside global/Oustide global ??

icon_surprised.gif

Comments

  • deth1kdeth1k Posts: 312Member
    NAT overload is PAT, meaning port address translation.
  • ralbertos21ralbertos21 Posts: 27Member ■□□□□□□□□□
    So NAT overload is PAT then... okay so my question now is why do they refer it to as "overloading?"



    Thanks
  • deth1kdeth1k Posts: 312Member
    Well, that's just Cisco way of configuring it and calling it an "overload".
  • xenodamusxenodamus Posts: 758Member
    I think of it as "overloading" that 1 public IP address with translations from a bunch of private ones using port numbers. As far as what PAT is, think about this -

    When you use NAT to translate an inside address to an outside address it takes 1 of each...as in:

    Inside 10.0.0.1 > Outside 65.5.53.216
    Inside 10.0.0.2 > Outside 65.5.53.217
    Inside 10.0.0.3 > Outside 65.5.53.218

    The purpose of PAT is to use port numbers to translate multiple inside addresses using 1 public address:

    Inside 10.0.0.1 > Outside 65.5.53.216:25000
    Inside 10.0.0.2 > Outside 65.5.53.216:26000
    Inside 10.0.0.3 > Outside 65.5.53.216:27000

    That way everyone on the inside network can be publicly routable using a single IP. Much more efficient use of the dwindling IPv4 address space.
    CISSP | CCNA:R&S/Security | MCSA 2003 | A+ S+ | VCP6-DTM | CCA-V CCP-V
  • instant000instant000 Posts: 1,745Member
    Please review this thread. It should clear up your questions.

    http://www.techexams.net/forums/security/88883-pat-nat-dnat-how-tell-one.html
    Currently Working: CCIE R&S
    LinkedIn: http://www.linkedin.com/in/lewislampkin (Please connect: Just say you're from TechExams.Net!)
  • d6bmgd6bmg Posts: 241Member
    Remember this sequence: Inside local -> Inside Global ----> Internet ----> Outside Global -> Outside Local (optional)
    This is the sequence of data flow.
    [ ]CCDA; [ ] CCNA Security
  • ralbertos21ralbertos21 Posts: 27Member ■□□□□□□□□□
    xenodamus wrote: »
    I think of it as "overloading" that 1 public IP address with translations from a bunch of private ones using port numbers. As far as what PAT is, think about this -

    When you use NAT to translate an inside address to an outside address it takes 1 of each...as in:

    Inside 10.0.0.1 > Outside 65.5.53.216
    Inside 10.0.0.2 > Outside 65.5.53.217
    Inside 10.0.0.3 > Outside 65.5.53.218

    The purpose of PAT is to use port numbers to translate multiple inside addresses using 1 public address:

    Inside 10.0.0.1 > Outside 65.5.53.216:25000
    Inside 10.0.0.2 > Outside 65.5.53.216:26000
    Inside 10.0.0.3 > Outside 65.5.53.216:27000

    That way everyone on the inside network can be publicly routable using a single IP. Much more efficient use of the dwindling IPv4 address space.


    You couldn't of explained this any better my friend, wow great stuff! Now i see the picture
  • ralbertos21ralbertos21 Posts: 27Member ■□□□□□□□□□
    instant000 wrote: »
    Please review this thread. It should clear up your questions.

    http://www.techexams.net/forums/security/88883-pat-nat-dnat-how-tell-one.html


    awesome thread just read it icon_cheers.gif
Sign In or Register to comment.