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Using a DSL Modem and a seperate firewall/gateway appliance.

N/A

Using a DSL Modem and a seperate firewall/gateway appliance.

One for the techies. I can connect through my DSL Modem without any problem, however I want to connect up my network through a security gateway (firewall, ids). In theory I believe that the gateway should be configured so that it's wan port matches the ip of the lan port on the modem. Whenever I try setting up both devices I cannot get a connection through them to the internet.

If anyone has any ideas - other than buying a combined device - I would be grateful, or even a link to setting up this type of scenario.

Internet --> DSL Modem -->ethernet--> Security gateway --> Internal LAN.

Thanks in advance.

howlehill
2 REPLIES
N/A

Using a DSL Modem and a seperate firewall/gateway appliance.

My advice is to get things working one step at a time.

Internet --> DSL Modem -->ethernet--> Computer

Once you have this configured, you should be able to use the current settings sued on the computer, to configure the WAN port of the Security gateway.

I would alos disable almost every protection possible, in order to confirm a working setup, then add parts one at a time.
ncreu
Grafter
Posts: 77
Registered: 13-08-2007

Re: Using a DSL Modem and a seperate firewall/gateway applia

Quote
If anyone has any ideas - other than buying a combined device - I would be grateful, or even a link to setting up this type of scenario.

You don't say which product brand you're using. I purchased a D-link DSL-502T: http://www.ebuyer.com/customer/products/index.html?rb=2917560119&action=c2hvd19wcm9kdWN0X3Jldmlld3M=...
It arrived a day earlier than promised, which was ideal because my ADSL activation was also a day early. I plugged it in and within a few seconds the connection was established.

I'd successfully bid on eBay for a Buffalo AirStation about a month earlier and set this up to connect two desktop PCs via ethernet and another desktop and two laptops via wireless.

I just plugged the D-link into the WAN port on the Buffalo and everything worked inspite of an apparent lack of continuity between the IP addresses of the separate bits of kit: http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=plusnet&Number=1472606

I'm now half way through my first month with this setup and don't appear to have suffered any more problems than the generally accepted PlusNet problems of having to refresh the browser when accessing linked pages on different IPs.

I switch everything off at night or when I'm not using the Internet. Startup involves firing up one of the PCs, switching the power on to the D-link and once a connection is established, powering up the buffalo. The setup for both the D-link and the Buffalo are via a browser window directed to their IP addresses.

The D-link has a configurable firewall, the Buffalo has intrusion detection and the PCs are all firewalled. I check the PlusNet usage page regularly and haven't detected any abnormal usage as yet. Perhaps it's still too early to be complacent but I hope that this setup will enable me to effectively manage my connection if I ever become a target.

I think the key is to keep a record of a working configuration before making selective changes. I have tried altering the 'speed' setting of the WAN port on the Buffalo from 'Auto negotiation' to '10Mbps half-duplex' but this just stopped everything working (I'd seen it reported that this might make the connection more stable) so I just changed it back again.
I don't know if this'll help in your situation but it might be of interest to someone else.

Richard