Hi,
I am setting up a linux box to serve as a firewall/gateway to a webserver at home. I can get the box communiticating fine on both nics with internal address, but when setting up either with my assigned external IP from my ISP, it wont communicate externally. If I connect my windows box directly to the DSL modem (D-Link 3001) I can use the external IP but not if I connect the linux box. I am running Mandriva 2005. Any thoughts as to what could be my problem?
I know that this is a little general and will add info as requested.
Thanks

Post the results of 'route -n' -- also give some indication of your IP set up. (External ISP, router, Linux box, windows box, etc)

I will post the remainder later (route table) but here is the first info. Hopefully it gives some insight. I assume with this setup, the external IP of the Asante is unimportant. Would connecting the Asante to the Dlink first possibly fix the setup?:

Telus
|
------------
|DLink 3001|
------------
|
----------------
|EXT IP (180...|
----------------
| Linux |
----------------
|INT IP (10... |
----------------
|
----------------
|Ext IP (180...|
----------------
|AsanteFR3004LC|
----------------
|Int IP (10..1 |
----------------
|
----------------
|Int IP (10.. |
----------------
|Windows box |
----------------

I can't read your update - sorry ;-(

Not sure what an Asante is, but I might be able to help if I can see your setup somehow.

Assante is a router. Here is a description (I will try to get the route info as soon as possible but any idea's until then are great).
My ISP is Telus. The ADSL modem that connects me is the DLink 3001. There is no manual authentication since I have external IPs, one of which is assigned to the router WAN port.
I was planning on putting the linux box directly to the modem so planned on the first NIC to have an external address rather than have the router in between. After this, I would have the router with the linux internal eth attached to an internal port and then the web server.
I hope this is clear enough for the time being. Thanks for the thought at least.

Here is the result of the route command.
When I set up the linux box and the windows box on the same router (actually putting the router between the DSL modem and the boxes) and put external IPs on each of them, the windows can be contacted externally as well as access the internet but unable to do either with linux. They are able to ping each other on the external addresses however.

Destination Gateway Genmask Flags Metric Ref Use Iface
255.255.255.255 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
180...0 180...10 255.255.255.0 UG 0 0 0 eth0
180...10 0.0.0.0 255.255.255.0 U 10 0 0 eth0
10...0 10...15 255.255.255.0 UG 0 0 0 eth1
10...0 0.0.0.0 255.255.255.0 U 10 0 0 eth1
224.0.0.0 0.0.0.0 224.0.0.0 U 0 0 0 eth0

What I'm not seeing is a default route (one for destination 0.0.0.0) on Linux. This would normally be the address of your router. Try issuing 'route add default gw xx.xx.xx.xx' Where xx.xx.xx.xx is the IP address of your router.

(What does Windows show when you do 'ipconfig' ? Does it match the Linux setup in terms of default gateway, etc?)

I have configured both to use a gateway external to the site assigned by the ISP. I guess the DLINK must only work in bridging mode since I do not have to use any internal GW. It works with windows so I assume this should not present a problem with linux. COrrect me if Im wrong.

I'm not really sure -- I don't have a clear picture of your setup at all -- All I can suggest is to do 'ipconfig' and 'route print' on Windows -- and 'ifconfig' and 'route -n' on Linux and see where the differences are.