Local IP vs Public IP

[mindeye]

Hello,

I am very new to networking over the Internet. I am currently trying to set up a server that will act as an FTP server and a Remote Desktop Server. I have a peer to peer setup with everything plugged into a switch, including my DSL modem. The modem is set for PPOE and has a Static IP address assigned to it. How do I use that IP to access my FTP server on my network. My FTP server has a Dynamic IP. Do I need to set the Modems Static IP address as an additional IP address on the server? If so....how? I just cant seem to access my ftp server with the Static IP address which is assigned to the modem...any suggestions??

Many Thanks,
Rogerr

 

[bcastner]

It sounds as if your modem has a small DHCP and router service, and you are using the modem DHCP service to assign NAT or local IP addresses to all connected machines behind the switch.

The key is to port forward ports 20 & 21 to the FTP server. If the FTP server is obtaining a new NAT local LAN IP on each boot, this becomes nearly impossible to handle.

If the modem/DHCP server will permit static IPs to be assigned, and it may; and if the modem/router service permits port forwarding, then you can resolve this issue.

Otherwise, place the modem in pure bridged mode and purchase an inexpensive broadband router that would allow you to use static IPs, and port forward. A four-port broadband router would permit you to daisy-chain your existing switch if your need more than four connections.

. the issue is unsolvable without port forwarding capability
. the issue is problematic if a static IP behind the NAT router for any device is not possible.

You do not mention what kind of FTP server you are offering, but the following discussion, while written in a Linksys router context, is universal as to the issues:

http://www.broadbandreports.com/forum/remark,1381832;root=equip,16;mode=flat