troubleshooting Question

Lan setup & router addition

Avatar of x_way
x_way asked on
NetworkingDNSNetworking Protocols
12 Comments1 Solution888 ViewsLast Modified:
Hi all,

I am currently working in a company which has moved premises and inherited a legacy type network of machines. I'm very computer literate, however networking is a new area for me, and my only knowledge is from 'how to' books. In trying to add internet connectivity to the inherited LAN, I've discovered a few problems and am out of my depth. Any help would be appreciated.
Please note that the network & setup is inherited, so if there are any ideas on how to improve its setup, it would be appreciated!

Current Setup:
Main network: Windows server 2000 machine, connected to the uplink port of a 24-port switch, and 15 clients connected to the ports of the switch. DHCP is switched off, the server IP address is and all clients are randomly assigned static IP's in the TCP/IP settings of their network cards up to about, with the subnet mask, and default gateway and DNS server set as the server's IP ( The network currently works fine for basic file sharing, accessing shared folders on the server, some network printing and use of a specialised order processing software package.

There is another isolated smaller network (in the sales office) which salesmen connect their laptops to which has internet access: This is a standard 4-port home/office ADSL router, with DHCP switched on, and gets used for basic fileshare and internet access to look at online sales catalogues.

Please see [URL=][IMG][/IMG][/URL] for a diagram.

To sum it up, internet access needs to be added to all machines on the main network, and there is no reason not to bring the laptops from the small network (who currently have the internet access) onto the main network.
To do this I purchased a VPN 4 port gigabit router, and an ethernet ADSL modem. Connecting the ADSL modem to the ADSL line, and plugging a computer into the ethernet port of the ethernet modem gave the computer internet access. However if the modem was then connected to the WAN port of the new router, no access was avaliable by connecting any machines to any of the client ports.

Please see [URL=][IMG][/IMG][/URL]

The only way I could get internet access from a client on the new router was to connect the WAN to an ethernet port of the old ADSL router, and place it in the DMZ of the old router. The ethernet modem is now sitting in a box unused.

Now that there was internet access going through the new router, I connected it up to a port on the main networks switch. I gave it an IP address in the same format as all the other network devices (, however alot higher than anything else to avoid any clashes as I am unaware of how the old addresses were allocated. I also switched the DHCP server in the router off. I then changed on all the clients conencted to the switch, their default gateway to the IP address of the new router, and the DNS server to the IP address of the router. Clients could then access the internet. However they could not access any network resources, such as network drives on the server. Strangely, changing the DNS server address in the clients TCP/IP settings BACK to the windows 2000 server IP ( allowed the network folders to be accessed again, however there was no internet access. The server has not been configured at all for internet access (I am not aware of a need to, or how to- I thought it was all in the default gateway and DNS setup of the clients). Sometimes, adding the new routers IP as the primary DNS server ( and the windows server as the secondary one ( the client would sometimes be able to access the internet, and file shares. This however is extremely temporary and can change between working and not without changing any settings.

The network is now connected as such: [URL=][IMG][/IMG][/URL]

This shows the physical connections and settings that rarely yet intermittently work.

When I talk about changing network card settings for default gateways and DNS servers, this is on the clients connected to the main switch. It is not necessary for the laptops in the sales soffice (physically connected to the old router) to be communicate with the server or any machine connected to the main switch.

I thought that by changing the default gateway and DNS address would proivide internet access, but without the DNS server set to the windows server machine, the clinets seem to be unable to access network resources. I am very puzzled!!

Is this due to how everything is physically connected (I am unsure if the server should be in the uplink port of the switch, I thought that was used to interconnect switches...), or the IP addressing, or a setting on the server etc?

Help would be much appreciated to 1) Allow me to fix this fairly messy problem and 2) Get my head round networking basics!

Join the community to see this answer!
Join our exclusive community to see this answer & millions of others.
Unlock 1 Answer and 12 Comments.
Join the Community
Learn from the best

Network and collaborate with thousands of CTOs, CISOs, and IT Pros rooting for you and your success.

Andrew Hancock - VMware vExpert
See if this solution works for you by signing up for a 7 day free trial.
Unlock 1 Answer and 12 Comments.
Try for 7 days

”The time we save is the biggest benefit of E-E to our team. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange.

-Mike Kapnisakis, Warner Bros