# How to configure DHCP server, Static NAT with 5 IPs (not just one) and gateway?



## jbarton (Feb 22, 2010)

I'm quite new to Linux systems and terminology but I have been computing since 1977 so I'm not all that green.  I've been working with networking since the early 80's and I have a fair grasp of what is happening there.  I can identify what I do to make my problem occur but I don't know what to do about it.

I have a system setup with the above configuration in mind; a DHCP server, 5 Static IP's and gateway for the LAN - all on one computer.  From what I have read and the posts I have read, this is a viable configuration.

I have been able to get the DHCP server to work correctly although I do not know how to keep it from complaining about duplicate entries for IPs that *it* issues.

The problem comes in when I try to make our two windows web servers public.  The approach I am taking is as follows:

Each web server's NIC is set for DHCP on each server.
They have their ethernet addresses entered in a fixed-address host entry in DHCPD.conf
Their assigned addresses are outside the range of the DHCP address pool.
Their (windows cmd) ipconfig settings are being correctly assigned by the DHCP server.

With this much done and natd_flags="" in rc.conf, every computer on the LAN has internet access and access with each other as desired.

Now to cause the problem to occur, which is the loss of internet access for the web servers, all I have to do is change the natd_flags to "-redirect_address 192.168.1.203 71.95.20.203".  Can someone tell me the correct syntax for making two redirects in rc.conf?  I did make a natd.conf which I can alternatively reference using  natd_flags="-f etc/natd.conf" which has both servers listed for redirect.  In either case the result is lose of internet access for the two servers.  Obviously, I'm doing something wrong but what could it be?  Everything works until I engage static NAT for a web server.

Apparently, this NAT is only meant to service one IP.  Is that the case?


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## J65nko (Feb 22, 2010)

From natd(8)

```
-redirect_address localIP[,localIP[,...]] publicIP
		 These forms of -redirect_port and -redirect_address are used
		 to transparently offload network load on a single server and
		 distribute the load across a pool of servers.	This function
		 is known as LSNAT (RFC 2391).	For example, the argument

		       tcp www1:http,www2:http,www3:http www:http

		 means that incoming HTTP requests for host www will be trans-
		 parently redirected to one of the www1, www2 or www3, where a
		 host is selected simply on a round-robin basis, without
		 regard to load on the net.
```


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## DutchDaemon (Feb 22, 2010)

> I'm quite new to Linux systems



Ehmm .. you know FreeBSD is not Linux, I hope?


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## jbarton (Feb 23, 2010)

J65nko said:
			
		

> From natd(8)
> 
> ```
> -redirect_address localIP[,localIP[,...]] publicIP
> ...




Not exactly what I asked.  I need the syntax for two address redirects in a natd_flags clause within rc.conf.  That's like two private IPs and two public IPs in a one-to-one assignment.  Many to one or one to many is of no use to me.  I see what you're saying though.  I had not seen that format before; thanks.


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