Two Subnets and Two Routers Only One Way Issue

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CBSYS

133 posts

Master Geek

#65064 28-Jul-2010 20:26

I have successfully setup two wireless routers one is a wireless modem router and the other is just a wireless router.

A: Dynalink wireless mordem and router (192.168.1.1; net mask 255.255.255.0; default gateway 192.168.1.1) . This one is link to ADSL to the WAN

B: Netgear WNR2000 wireless router (172.16.0.1; net mask 255.255.255.0; default gateway 172.16.0.1)

B connects into A with its WAN port to A's LAN port and B's ip address in A network is 192.168.1.2

My issue is that I can only see A network's computers from B network, but not the way back. I would like to keep two diffrent networks for testing purpers. Is there anyway let me can see and access computers both way A2B and B2A?

Or I'm doing something wrong that could not get it work. Please help guys. Cheers,

Alvin

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133 posts

Master Geek

#358006 28-Jul-2010 22:52

anyone? Please help cheers,

Fraktul

836 posts

Ultimate Geek

Trusted

#358022 28-Jul-2010 23:26

Probably because B has NAT, SPI etc enabled and/or A has no route for 172.16.0.0/24 in its routing table and is by default routing to its WAN port.

Turn off NAT/SPI/Firewall on B, Add a route for 172.16.0.0 255.255.255.0 to 192.168.1.2 on A. Make sure B uses a static IP on its WAN port connect to A of 192.168.1.2 and that A has a DHCP ip poor of 192.168.1.3-254 however.

Aaroona

3196 posts

Uber Geek

#358025 28-Jul-2010 23:36

May I ask why you have used the WAN port to connect the two routers together? seems pointless unless you were running it in bridge mode..

you might as well just plug it into a lan port, have one DHCP server, one firewall etc.

unless, like I said, there is a reason you've done it that way.

CBSYS

133 posts

Master Geek

#358508 29-Jul-2010 16:24

Fraktul: Probably because B has NAT, SPI etc enabled and/or A has no route for 172.16.0.0/24 in its routing table and is by default routing to its WAN port.

Turn off NAT/SPI/Firewall on B, Add a route for 172.16.0.0 255.255.255.0 to 192.168.1.2 on A. Make sure B uses a static IP on its WAN port connect to A of 192.168.1.2 and that A has a DHCP ip poor of 192.168.1.3-254 however.

I've done everything you suggested, but its still not working, the rout i added like this as following. Not sure if it's right.

Destination Netmask Gateway WAN Interface Delete
172.16.0.0 255.255.255.0 192.168.1.2

CBSYS

133 posts

Master Geek

#358515 29-Jul-2010 16:30

Aaroona: May I ask why you have used the WAN port to connect the two routers together? seems pointless unless you were running it in bridge mode..

you might as well just plug it into a lan port, have one DHCP server, one firewall etc.

unless, like I said, there is a reason you've done it that way.

the reason I've done it this way is that I would like to use 2 routers and both of them have internet connection. I did not want to turn the DHCP off on B and use it like a switch cause i need two subnets for testing. Cheers,

webwat

2036 posts

Uber Geek

Trusted

#358643 29-Jul-2010 18:37

Then setup your modem to use a different subnet on the port your other router is connected to. The only reason to have a second NAT firewall/router behind your main firewall/router is because its protecting something that you dont want to be accessible from your main LAN. Obviously the effect is that the protected LAN will not be accessible without port forwarding or other NAT traversal.

If you just need subnets, then your gateway needs to route between the subnets. Otherwise, the function of a NAT router is to hide everything behind its public WAN address.

Time to find a new industry!

CBSYS

133 posts

Master Geek

#358747 29-Jul-2010 20:00

webwat: then your gateway needs to route between the subnets.

how can i do this pls? Cheers,

Equinox IT

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Fraktul

836 posts

Ultimate Geek

Trusted

#358844 29-Jul-2010 21:05

If you have not turned off NAT/SPI/Firewalling on unit b then you didn't do everything I suggested :)

If you want to know how to do this then RTM.

CBSYS

133 posts

Master Geek

#359063 29-Jul-2010 23:33

Fraktul: If you have not turned off NAT/SPI/Firewalling on unit b then you didn't do everything I suggested :)

If you want to know how to do this then RTM.

mate, i've turned NAT/SPI/Firewall verything off already at the first stage. but it just not working for me. :(

Also, I'm not quite sure about what you mean RTM?

webwat

2036 posts

Uber Geek

Trusted

#359135 30-Jul-2010 02:28

CBSYS:
webwat: then your gateway needs to route between the subnets.

how can i do this pls? Cheers,

You do it by: "setup your modem to use a different subnet on the port your other router is connected to."

That means your main router has two different subnets allocated for different LAN ports. Since you want the LAN subnets to talk to each other, you do NOT want a WAN on the second router because obviously this would firewall everything connected to it.

Time to find a new industry!

webwat

2036 posts

Uber Geek

Trusted

#359136 30-Jul-2010 02:30

CBSYS:
Fraktul: If you have not turned off NAT/SPI/Firewalling on unit b then you didn't do everything I suggested :)

If you want to know how to do this then RTM.

mate, i've turned NAT/SPI/Firewall verything off already at the first stage. but it just not working for me. :(

Also, I'm not quite sure about what you mean RTM?

If all else fails, read the.... manual.

Time to find a new industry!

berend

62 posts

Master Geek

#360596 31-Jul-2010 12:08

CBSYS: My issue is that I can only see A network's computers from B network, but not the way back. I would like to keep two diffrent networks for testing purpers. Is there anyway let me can see and access computers both way A2B and B2A?

What is see? Can you ping from A to B and from B to A?

CBSYS

133 posts

Master Geek

#360758 31-Jul-2010 19:18

i can ping from B2A but not A2B

berend

62 posts

Master Geek

#361307 2-Aug-2010 06:54

CBSYS: i can ping from B2A but not A2B

Either a firewall is blocking you or you have a NAT traversal issue. Try traceroute to see how far you get.

Given your setup, it is probably the Netgear WNR2000 as you try to ping from A to B using it's WAN port. I.e. it thinks someone in the big outside world tries to ping and that's usually not allowed (firewall) or possible (NAT).

CBSYS

133 posts

Master Geek

#361447 2-Aug-2010 11:36

I've already turn the SPI firewall and NAT Filtering off and ticked Respond To Ping on Internet Port.

Somehow, it just not working for me.

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