Berkeley CSUA MOTD:Entry 20709
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2025/05/24 [General] UID:1000 Activity:popular
5/24    

2001/2/27 [Computer/Networking] UID:20709 Activity:high
2/26    router question: sharing static ip address, but pc's in lan have own
        machine names and web servers. how does router know which machine a
        url refers to if the url just has the ip address in it?
        \_ What's running NAT?  Is it a linux/windoze box or one of those
           NAT hubs/switches/routers?
          \_ pc 's and linksys router.
             \_ Is the idea you want your web server accessible from
                outside your LAN?
                \_ yes but there are 2 computers w/ web servers, both need to be
                accessible. The hope is that the router would disintiguish by
                MAC address but the 2 machines would have the same ip.
                \_ Let's say I request the web page
                   <DEAD>www.yermammy.com/foo/bar.html<DEAD>
                   Your browser will put the following in the HTTP request
                   header:
                   Host: <DEAD>www.yermammy.com<DEAD>
                   Now, I'm not sure if linksys routers do this, but the
                   way it would work is that the router would see the
                   packet is going to port 80, look for and interpret
                   the host field, look at a mapping of host field
                   settings to local IP addresses (which presumably you
                   have set), and finally direct the packet to the IP
                   address of the appropriate web server.
                \_ how could the router tell which IP packet is destined for
                   which machine?  Incoming IP packets aren't going to contain
                   MAC addresses.  You'll need to have the web servers use
                   different ports.
                   \_ Yeah, this is the most straightforward way.
                      <DEAD>www.yeremammy.com<DEAD> (port 80)
                      <DEAD>www.yerbrother.com:81<DEAD>
                      and then port forward.
                   \_ unfortunately, the 2 "web servers" are actually DAQ board
                      cards that require an IP addresss but use the same port
                      (no way to change port) even if they have unique IP
                      addresses, the outside would still point to 1 ip
                      address/hostname and same port for both of them.
                      \_ web server 1:  192.168.0.1:80
                         web server 2:  192.168.0.2:80

                         port maps:
;                        router:80 -> 192.168.0.1:80
                         router:81 -> 192.168.0.2:80
                         \_ You've gotta stop posting useful info to the motd.
                            People will come to expect something better than
                            the typical trolling and then what?
2025/05/24 [General] UID:1000 Activity:popular
5/24    

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