Create Multilpy FTP Sites Using the Same IP

Sling_Blade used Ask the Experts™
I have a Windows Server 2000 running IIS and is used as a webserver. The server has one internal IP address assigned to it ( and we are behind a firewall.

I have several different websites that use the server. Each website is setup in the DNS which redirects to the internal IP and I then use the host header name to distinguish between the sites in IIS.

What I want to do is to setup a different FTP site for each website so each website owner can access each site independently from each other.

From what I have found so far is that FTP requires a different IP for each site, is that correct?

Is there a way to create a different FTP site for each website if the websites all use the same internal IP?
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Sure... the ftp sites would simply need:
a) unique DNS names internally AND externally.  Remember that you'll probably use different IPs for behind the firewall than from the outside.    You'll also need an external static on your firewall for EACH ftp IP number visible to the outside if you intend to expose the ftp sites to the outside world.
b) add the IP numbers as secondary IP addresses to the NIC of the server
c) create new FTP sites, but instead of selecting "all available" for the IP- choose the IP for each FTP instance.  Make sure for your own sanity that you rename each ftp server service to match the appropriate website.
The reason you can't set up the same kind of redirection is that ftp services "listen" on port 21 for inbound traffic.  Only one server can listen (to my knowledge anyway) to any given tcp/ip number + port combination.

One other (theoretical) option is a little tricker, but likely still possible.  You might be able to move the port that each ftp is listening on (normally 21), and create multiple servers using the SAME ip, but your pathing will get complex  (  Some tools can be configured to use non-standard ftp ports, but many cannot... so be careful if you try this route.


Can i have static routing with one external IP to several internal IPs?

static (, netmask
static (, netmask
static (, netmask


If I can create secondary IP's on the nic then I could change the IP in the DNS for the website itself and set the ftp site up with the same IP as the website.

I didn't realize I could set up secondary IP's, very nice. That will save a lot of trouble.

I will need to set up static mappings in the router and change the IP's for each DNS stetting to match the new static mapping. Does this sound right?

Are there limitations to setting up secondary IP's?

a) you can't have static routing from one to many... at least not on 95% of the routers out there that are doing NAT.  You'll need one external IP address for each individual IP address you want to expose.
b) yes, you can create secondary IP's on the server NIC.  Just go to tcp/IP, IP settings and Advanced.  You can add additional IP's there.
c) yes, set up the extra IP's on the server internally.  Then map EACH to an external static on your router.  Then create DNS entries for your internal hosts, and separate DNS entries for your external hosts (usually done through your ISP).

Btw, you can do this same kind of thing for your www sites as well as your ftp sites, if you want to make it easier to understand... but one caution - apparently Sharepoint sites don't much like the multiple IP address approach... they like the host redirection that you are already familiar with.

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