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Hippiekiller

2 lans wont talk to each other?

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Information

 

Netgear DG834G v4 ADSL Modem / R outer

LAN IP: 192.168.1.10

Also acts as a DHCP Server and plugs into a dlink switch (but as far as i can tell there is no configuration on the switch)

 

Computer A

ip address: 192.168.1.204

Subnet Mask: 255.255.255.0

Gateway: 192.168.1.10

 

This plugs into the switch.

There are also about another 5 computers that plug into the switch and can access the net and browse other computers on the LAN without any problems.

 

DLink DIR-300 Router pluged into the switch

"Internet Connection Type" : Static IP

WAN Port goes to the dlink switch

WAN IP: 192.168.1.239

Subnet: 255.255.255.0

ISP Gateway Address: 192.168.1.10

Primary DNS: 192.168.1.10

 

Computer B

Connection-specific DNS Suffix . :

Dhcp Enabled. . . . . . . . . . . : No

IP Address. . . . . . . . . . . . : 10.182.0.12

Subnet Mask . . . . . . . . . . . : 255.255.255.0

Default Gateway . . . . . . . . . : 10.182.0.1

DNS Servers . . . . . . . . . . . : 10.182.0.1

 

 

Computer B can see Computer A

But Computer A cannot see computer B and i need to be able to do it this way.

 

I am thinking i need to set up some sort of route on the Netgear Router and maybe also another on the Dlink but i am not sure what.

Could i get some help please.?

 

I added a static route on the Netgear router which was Active and Private (LAN only)

Destination: 10.182.0.1

IP Subnet: 255.255.255.0

Gateway IP Address: 192.168.1.10

Metric: 2

 

now from computer A i can ping the dlink router (10.182.0.1) but cannot ping Computer B.

When i do a "tracert 10.182.0.12" i get a reply from 192.168.1.10 that the destination host unreachable.

Edited by Hippiekiller

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Why on earth do you have a second router at all?

 

Computer A can't see computer B because the D-link router can only perform NAT in one direction.

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Why on earth do you have a second router at all?

 

Computer A can't see computer B because the D-link router can only perform NAT in one direction.

 

We have a second router because............................... well the guys that want it set up this way, say it is for security.

I am doing this out of interest and trying to make someones life a little easier.....although making mine harder in the process at the moment, lol.

 

hmmmm cant i add some sort of route to the dlink?

I am using ping and tracert to test the connections.

 

All computers are running windows XP.

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For two way communication, you will need to disable NAT on the Dlink router. (I will assume it is enabled)

Then, in the DG834 you will need to setup a static route to the 10.182.0/24 network, using 192.168.1.239 as the gateway. Use 2 for the metric, though I guess it should not matter too much what it is.

 

If you can not disable NAT on the Dlink router, assuming you have set up everything correctly, you should already have one way communication from the "LAN" side of the Dlink router to the "WAN" side (including the internet). What will happen is that requests coming from the "LAN" side of the router will get translated as coming from 192.168.1.239, which is generally still ok.

 

To go back the other way, you can try setting up port forwarding in the Dlink router, however this may cause issues if talking about multiple computers and multiple services.

 

Can I ask what is on the "LAN" side of the router? And why it is there?

 

Edit: I just looked up the DIR-300 - My guess is that you should be able to disable NAT on it, IF needed.

What are you actually trying to achieve? What should be able to talk to what? And what is blocked?

There is little point in having two separate networks for security, if you just allow all traffic between.

Edited by Chancellor

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We have a second router because............................... well the guys that want it set up this way, say it is for security.

My spider sense is telling me he's not that intelligent.

 

You need a route set up on either Computer A, or on the Netgear, that forwards all traffic to 10.182.x.x to 192.168.1.239.

 

Wait a sec, that brings up an interesting question, how will the DLink respond when it gets an incoming packet on the WAN side wanting to go directly to an IP on the LAN side? I would've imagined it would just drop it blindly. There shouldn't be any packets like that on the WAN side.

 

Rob.

 

Alternatively you can put Computer B on the DLink's DMZ. Then access Computer B via the DLink's IP address.

 

This offers zilch in the way of security, though. It's needless and silly.

 

Rob.

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Off the shelf routers generally can't perform any routing from WAN to LAN. The can port forward, but that's not routing, really.

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The D-Link doesn't support a bridged mode of sorts? Most routers do, I would've thought that would achieve what he wants.

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Bridge mode refers to ADSL modem/routers, and allow you to disable the routing function of the device. This makes the device function only as a modem.

 

Disabling NAT will enable "classical routing" (in lack of a better term coming to mind). Depending on the device, you can still perform firewall functions on the device, however with a lot of consumer all in one boxes, the results vary.

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What Chancellor said about about disabling NAT and adding static routes. This still isn't a good idea though (as already pointed out) and is likely to add complexity (if it even works) rather than security, especially with these types of cheapo routers.

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