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Two seperate lans sharing one internet connection

Posted on 2007-12-06
Medium Priority
Last Modified: 2008-07-14
Hi all,

Heres whats up. Im trying to create a test network which incorporates several different servers and client machines running SQL services as well as third party software such as Made2Manage and others which are used to communicate with various machines on the manufacturing floor. The problem that i have is that i noticed that our "Main" Made2manage Server can ping the primary lan which is a big concern for us, but we cannot ping the second lan from the primary lan. Our current setup is as follows:

1.netopia router which serves up our internet connection among other things.  

2.Linksys WRT54gs router running dd-wrt (latest version) connected to a switch that is directly connected to the primary netopia router.

Wan IP coutesy of dhcp from netopia
Local ip:
local Sub:
local GW:
local dns:

3. Linksys wrt300n router connected to the Linksys w/ dd-wrt

Wan ip Courtesy of dhcp from WRT54gs
Local ip:
local Sub:
local GW:
local dns:

w/DHCP off

As is we can get connectivity to the interweb which is a must since remote access via gotomypc will be used over the weekend but as stated above we want to completely separate contact of any kind betweeen the two networks while mainting internet connectivity.
Is this possible in general, with our current hardware or will we need more robust equipment?
Thanks in advance!

Question by:fwecoadmin
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Expert Comment

ID: 20422669
it sounds like the primary lan might have a lower security level than the other lan.  for instance, on my firewall, the primary lan is 100, the dmz is 10 and the internet is 0.  or it might be an access rule that is allowing traffic from the other to the primary.
LVL 11

Expert Comment

ID: 20422752
My inclination is to connect wrt300n to netopia, not WRT54gs.

Author Comment

ID: 20451184
The Security on our primary lan is about as tight as it gets so i dont believe thats the issue. And as far as connecting the 300n only...well thats been done already with the same results.
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Author Comment

ID: 20593083
Unfortunately, none of these really provided a solution and since this post we've been using m0n0wall loaded on a cheap desktop.  So far this firewall product seems to be doing the job just fine providing a duplicate test network using the same gateway without interfering with our live operations.  

Use this:


Expert Comment

ID: 20823153
Firstly, update your firmware...
If your firmware allows, check out the Netopia's VLAN option.
Alternately check out the Netopia's Static Routes or IP Static ARP (IP to MAC map)

This should take care of your needs.


Accepted Solution

fwecoadmin earned 0 total points
ID: 21968685
Sorry for the delay.  We used another solution some time ago, not mentioned here.  None of these worked for us and we ended up using the WRT54GS as an Access Point and went into a PC loaded with M0n0wall ( ).  

Using M0n0wall as a firewall we created a Sub-LAN, by assigning a Client IP to it's WAN side, within the Primary LAN and configured the routing tables to point to the Gateway on the Primary LAN.

The WRT54GS ended up being used as just another radio without any DHCP or router properties.

Expert Comment

ID: 21973157
the sub-LAN and VLAN, pretty much the same functionalyty...  congrats on getting your issue resolved...

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