# Port Forwarding Behind two routers



## logansosa (Dec 29, 2004)

I am having a problem with forwarding ports. I have two routers, the first is connected to the modem and serves as the LAN1 and there are two computers connected to it, this router is connected to internet. The second is about 50 feet away and it is connected to the first by ethernet cable. This router is LAN2 and then transmits the the signal to the rest of the computers in my house via WLAN. Now I know how to port forward with one router and I thought I knew how to do it behind two routers but all in all the port is still not open, here is what I did: 

1) R1 is Dlink DI-624 R2 is Linksys WRT300N
I have forwarded Port 3036 and 3037 from R1 to R2's external Ip. I then forwarded port 3036 and 3037 from R2 to my Notebook which has Utorrent running and two ports that I use, those obviously being 3036 and 3037. I set it up that way since I have two static Ip's for my computer one for the LAN and one for the WLAN, it just depends if I am at my desk or about the house. 

I looked at portforward and this is what it said to do and somehow the port is still closed and I don't know how. 

For a little more detail: R2 shows an internet IP address of 192.168.0.104 which abviously has been assigned to it from R1 and this is the IP I am curretnly forwarding to. But how do I give my router a static external IP. And to tell the truth I am not 100% understanding external vs. internal Ip, external is suppose to be WAN right? The IP address that the internet sees, and the internal is suppose to be LAN or private right? the one that only the internal network users can see, so How do I get my R2 to have a static external so that my R1 can consistently forward to it?

Let me know if any more info is needed, thanks for any help to come.

Logan


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## jmwills (Sep 28, 2005)

You can only have one DHCP server per LAN segment. Disable DHCP on the second rouetr and give it an static IP Address outside the sope of the firt router. Poft forward from the first router to a static Ip address of any machine on the new LAN.


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## jackdw (Jul 1, 2005)

On your first router, set up the port forwards, NOT on the second one though. The one with the connection manipulates the incomign data to change it from saying it meant for your external IP to the one you set it up to.

DATA-81.25.1.5 (internet IP) Router 1 changes it to DATA-192.168.1.1 and gets sent to router 2, router 2 sees 192.168.1.1 and forwards it there.


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## JohnWill (Oct 19, 2002)

If you configure the secondary router properly, it won't require port forwarding, and you'll have a single subnet.

Connecting two SOHO broadband routers together.

Configure the IP address of the secondary router to be in the same subnet as the primary router, but out of the range of the DHCP server in the primary router. For instance DHCP server addresses 192.168.0.2 through 192.168.0.100, I'd assign the secondary router 192.168.0.254 as it's IP address.

Disable the DHCP server in the secondary router.

Setup the wireless section just the way you would if it was the primary router.

Connect from the primary router's LAN port to one of the LAN ports on the secondary router. If there is no uplink port and neither of the routers have auto-sensing ports, use a cross-over cable. Leave the WAN port unconnected!


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## logansosa (Dec 29, 2004)

Thanks guys, all is well, but I had to forward from first router to second router static ip, for some reason I couldn't forward from first router directly to my pc under second router. 
But the ports are now open and it's working fine. 
thanks again

Logan Sosa

oh and quick question about bandwith, my connection is a 10 Mb connection, does that mean 10 Mega Bits or bytes, and is lets say if my total connection speed is 1.25 mega bytes per second for downloads and 130 Kilobytes per second for uploads, then if I am uploading at max (130) with utorrent, would that disable any other pc from uploading at all like let's say an email. I was under the impression that bandwith is a limited amount and it is total and not per computer.


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## jackdw (Jul 1, 2005)

10megabit connection. There are 8 bytes in a bit. 10megabit divide by 8 = 1.25, 1.25 megabytes a second yes.

Uploading, no. The router will share out the the bandwidth evenly. And pelase don't mention torrents etc on here. A mod will pick it up and close the topic.


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## JohnWill (Oct 19, 2002)

As mentioned, we don't help with illegal activities here.


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## logansosa (Dec 29, 2004)

Any ideas why, even though my settings are the same, my specified port to forward to is inconsistent with it's pathway, some times it is open, and sometimes it is closed, once it was closed for about 5 minutes when I first turned on the PC but then it was open, just like that. Now it is closed and I am not sure of ALL aspects that affect open and closed ports. Is there any way I can manually open specified ports? 
And just for clarification, I am not the only person in house that has admin capabilities, but like I said i checked both router settings and they have not changed.


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## researcher (Dec 27, 2007)

JohnWill said:


> If you configure the secondary router properly, it won't require port forwarding, and you'll have a single subnet.
> 
> Connecting two SOHO broadband routers together.
> 
> ...


Hi JohnWill, the steps you provided here are similar to the one I found at portforward.com, (link provided for reference)
http://forum.portforward.com/YaBB.cgi?board=Knowledge;action=display;num=1133918703

So instead of double portforwarding, i opted to convert my second router into a switch/hub/WAP. I must note that this second router is a linksys wireless G model WRT54GS. I performed all the steps and I am still able to access the internet afterwards but the problem I am having is that I can't play online games (i.e. Starcraft, MapleStory, etc.). I tried forwarding ports on the FIRST router (which is a wired D-Link DI-604) but to no avail, I still cannot play these games!
I also use Windows XP firewall that comes with service pack 2 and I opened the same ports in it. It still does not yield desirable results.

The only reason why I have a second router instead of a switch/hub is because I needed a wireless router so I can go online with my laptop.

Here's a rough diagram of my network setup (credit goes to MarkM, an admin from portforward.com; I slightly modified it though and I drew 3 red lines out of 1 LAN port for simplicity)
NOTE: the red lines are simple blue ethernet cables









I appreciate any help you can provide regarding this problem.

Thanks in advance. 
- researcher


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## JohnWill (Oct 19, 2002)

What is the issue. "Undesirable results" doesn't tell me much. 

If you followed my guide exactly, this should work.


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## researcher (Dec 27, 2007)

basically i cannot play online games despite port forwarding and being able to access the internet.


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## JohnWill (Oct 19, 2002)

Can you play the game connected to the primary router? I'm thinking that the secondary router configuration isn't the issue here.


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## researcher (Dec 27, 2007)

Hi JohnWill,

to answer your question, i tried playing these games on a computer that is behind the 1st router, and I am able to play them. 

what confuses is why the computer behind the second router can't play these games since my network should be 1 LAN now instead of 2 because i converted the second router to act like a switch.


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## JohnWill (Oct 19, 2002)

If you did the conversion properly, there should be no issue. I've done this on a number of networks, including mine, and the second router is transparent. Something is still in the mix that shouldn't be there.


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## researcher (Dec 27, 2007)

JohnWill,

Is there some kind of network test to see if my second router really is really transparent? 

-researcher


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## JohnWill (Oct 19, 2002)

Just connecting a computer to it. I've done this many times, and if you have disabled DHCP and left the WAN configuration at Dynamic IP, it's pretty much all you need to make the routing functions disappear.

Obviously, you MUST NOT use the WAN port, but only the LAN ports.


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## jackdw (Jul 1, 2005)

Tried and tested is JohnWill's technique. I use it here, saved me a few quid in buying a switch but also meant I could have an additional wireless network.

You have done something wrong, if it's set up correctly it should be a switch which doesn't edit the data at all, just directs it.


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## AdamInc (May 26, 2006)

thanks for all the responses helped with a problem of mine, but you have to remember torrents arent illegal, if your using bit torrent to transfer big files that are yours its not illegal i'm not sure why ppl associate torrents with illegal content.


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## TechGuy (Feb 12, 1999)

Torrents are associated with illegal activity because they're often used for it. You're right, of course - there are plenty of legal uses, too.

When you connect via your wireless network, try disabling your other NIC(s). I've had a problem with Starcraft, Command & Conquer, etc where they will only look at the first NIC.


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## researcher (Dec 27, 2007)

Is anyone familiar with the web interface of linksys? I'm not sure where to configure the WAN to dynamic IP (or is this default?)

also, i read somewhere else that i might need to turn off NAT on the second router. how do i do this? and one more thing, how to change from gateway mode to router?

i'll provide a quote from another forum for reference:


> ^^^^ correct. I setup wireless routers as access points(wireless switch basically) all the time.
> 
> Disable the DHCP. also mighthave to turn of NAT. or change from gateway mode to router(linksys, they word it totally wrong but thats what you do). I'm not sure exactl what the setup or wording is for the netgear but you get the idea. And just go from the linksys into one of the lan ports o nthe netgear(not the WAN). you should be golden.


can someone explain why I successfully have internet connection for the computer behind the second router (wireless, it's DHCP disabled, nothing plugged to its WAN port) but i am unable to connect and play online games (i.e. starcraft, maplestory, etc.)

EDIT: i believe i may have found a possible answer but i don't know what to do exactly








i'm thinking i should change the router mode from "gateway" to "router" as shown in the screenshot, but i am not sure what values to specify and other required configurations in the screen to make the router transparent. anyone?

EDIT 2: 
i tried DMZ using the static ip address i assigned for the computer behind the second router but it did not work.

also, i must note that there is no physical ethernet cable running between the lan port of the first router (D-link) to the lan port of the second router (linksys). instead, an ethernet cable is plugged to the lan port of the linksys but the other end of the cable is plugged into a phone jack on the wall which i'm sure connects to the lan port of the d-link otherwise i wouldn't get internet connection.....the only problem is that i can't play online games!


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