port forwarding question

Discussion in 'Computer Support' started by bigtom, Mar 14, 2006.

  1. bigtom

    bigtom Guest

    shdsl, cisco828 modem/router, 8porthub, 3 computers on lan, winxp pro.

    A computer on my lan(10.0.0.7) needs port 80 and a few others forwarded
    to it. Does this mean the other computers wont have access to those
    ports?
    bigtom, Mar 14, 2006
    #1
    1. Advertising

  2. bigtom

    Meat Plow Guest

    On Tue, 14 Mar 2006 23:21:53 +1100, bigtom wrote:

    > shdsl, cisco828 modem/router, 8porthub, 3 computers on lan, winxp pro.
    >
    > A computer on my lan(10.0.0.7) needs port 80 and a few others forwarded
    > to it. Does this mean the other computers wont have access to those
    > ports?


    No.
    --

    Pierre Salinger Memorial Hook, Line & Sinker, June 2004
    Meat Plow, Mar 14, 2006
    #2
    1. Advertising

  3. bigtom wrote:

    > shdsl, cisco828 modem/router, 8porthub, 3 computers on lan, winxp pro.
    >
    > A computer on my lan(10.0.0.7) needs port 80 and a few others forwarded
    > to it. Does this mean the other computers wont have access to those
    > ports?


    Don't mix target with source ports. A webserver running inside your NATted
    LAN will want to be accessed with the common public IP, so the router
    forwards incoming (from the evil net) requests for <your public IP>:80 to
    that 10.0.0.7:80. A webbrowser on the same computer or any other can freely
    access other webservers at the same time.
    Btw. client communications are usually initiated from high numbered ports.
    Have a look at "netstat -n" from a commandline, while you are "surfing".
    --
    vista policy violation: Microsoft optical mouse detected penguin patterns
    on mousepad. Partition scan in progress to remove offending
    incompatible products. Reactivate MS software.
    Linux 2.6.14-mm1 [LinuxCounter#295241,ICQ#4918962]
    Walter Mautner, Mar 14, 2006
    #3
  4. "bigtom" <> wrote in message
    news:...
    > shdsl, cisco828 modem/router, 8porthub, 3 computers on lan, winxp pro.
    >
    > A computer on my lan(10.0.0.7) needs port 80 and a few others forwarded
    > to it. Does this mean the other computers wont have access to those
    > ports?
    >


    Yes as far as port forwarding on the router for unsolicited inbound traffic
    for those ports so that client machines on the Internet can make contact
    with the server programs running on the machine for those forwarded ports,
    that kind of traffic can only be directed to the static LAN/IP machine the
    traffic is being forwarded to on the LAN.

    A browser like IE or others that initiated contact with a site from behind
    the router is called solicited traffic and that kind of inbound traffic will
    be directed to the soliciting machine on port 80 while unsolicited inbound
    traffic will be directed to the port forwarded LAN IP/machine.

    Duane :)
    K-Man hater Duane, Mar 14, 2006
    #4
  5. bigtom

    Rick Merrill Guest

    bigtom wrote:

    > shdsl, cisco828 modem/router, 8porthub, 3 computers on lan, winxp pro.
    >
    > A computer on my lan(10.0.0.7) needs port 80 and a few others forwarded
    > to it. Does this mean the other computers wont have access to those
    > ports?
    >


    The other computers could "access" as a client, but the computer with the forwarded port is where the servers run (http ::= port 80); but you would not want the other computers to also be running http servers (unless you have a much more sophisticated system with server load sharing)
    Rick Merrill, Mar 14, 2006
    #5
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Salus
    Replies:
    4
    Views:
    2,062
    Aaron Woody
    Oct 21, 2003
  2. James
    Replies:
    1
    Views:
    907
    Walter Roberson
    Aug 4, 2004
  3. Roger Baker
    Replies:
    11
    Views:
    1,399
    Tim Bray
    Feb 7, 2007
  4. Walter Roberson

    Re: Newbie Port Forwarding Question

    Walter Roberson, Dec 10, 2006, in forum: Cisco
    Replies:
    2
    Views:
    427
    Wil Schultz
    Dec 11, 2006
  5. ToyalP2
    Replies:
    7
    Views:
    1,501
    ToyalP2
    Jan 7, 2008
Loading...

Share This Page