doubts about port forwarding

sharathg786 · 10-26-2006, 08:01 AM

Hi, i'm a newbie in networking.

My question is, if any person enters my IP address in his browser it takes him to my router configuration page(when i'm not running any server)
now if i forward my HTTP port 80 to point to my system & I close the HTTP port on my system, what does he see? also if he uses a port scanner does it show HTTP as open (which is on my router) or shows it as closed (which is on my system)

please correct me if i sound stupid, i'm new to this networking thing.

acid_kewpie · 10-26-2006, 08:17 AM

are you sure other people see that? normally a web interface on a router will be visible only from the internal lan and the router will by default do absolutely nothing with requests on port 80 externally. i'd be seriously pissed with an ADSL router if it did...

if you are not portwarding specifically then the port is officially closed as far as a port scanner will care. if it's open it will return the data from the internal node.

sharathg786 · 10-26-2006, 11:22 AM

thanx for the reply, actually i'm not sure, i saw this on some forum website & was concerned about securing it someway. I tried using nmap on my IP address(some websites show our IP address like whatismyipaddress[dot]com) & found HTTP & telnet open.

entering this IP on my browser took me to my router configuration page, so is that because i'm inside this network that i get to see the router configuration??

acid_kewpie · 10-27-2006, 02:32 AM

it certainly should be. if you confgiure your browser to use a proxy and use the proxy to reflect back to your router you'll be able to see exactly what you would do from the outside. yoru isp normally has open proxies you can use, but if you can't find it, there are plenty of open proxies out there.

sharathg786 · 10-27-2006, 07:30 AM

thanx it really helped me

amitsharma_26 · 11-01-2006, 12:02 PM

Try this as well..
iptables port forwarding / natting basics - http://amitsharma.linuxbloggers.com/portforwarding.htm

Regards,
Amit..