Networking Issue

[DanTheTechMan]

Hi, I'm only on this forum when I have a tech problem I can't solve myself (which isn't that often, and this is where I come to solve them).  So, that explains my long absence.  Anyway, I am having some networking trouble. I have two routers, (one directly connected to the internet) connected to each other through a powerline adapter (to avoid running a 100+ ft cable across my apt.). I would like both of them to be DHCP servers (I had this successfully working before).  My issue is Computer "A" (the one directly connected to the internet) gets internet fine, but computer "B" gets no internet (when the router is present).  When I remove the second router, I get internet on computer "B".  I would like to use both routers, both as DHCP servers. All of my computers now run windows 7 SP1.  Any help would be greatly appreciated.

[Shane]

You normally cant.
http://www.pcwintech.com/what-port-forwarding-nutshell

This is because each router has to have a different LAN IP then it does on the WAN. It sounds like what you should be doing is instead of a 2nd router is to just use a switch instead.

Then everything will get dhcp and what it needs from the one router. and the switch will give you all the extra ports you need if you have a big enough switch

It is possible to have the 2nd router act as a switch only. You have to disable DHCP in it and then the cable plugged into the WAN port will get plugged into one of the LAN ports instead and then the work stations will pull DHCP from the first router instead. I have done it that way before when I was in an emergency situation and I needed a switched replaced asap, so I made the router act as a switch.

Every router has its own local network, this is why your having so much trouble then LAN and WAN cant be on the same network.

Shane

[DanTheTechMan]

Ok, just an update on what i've done to hopefully resolve this problem:  I've removed router "A" and put router "B" in it's place (so I'm down to just one router now).  The powerline adapter on computer "B" is a direct connection, which now gives me internet.  The whole purpose of having two routers (both acting as dhcp servers) was so I could have one specifically for my own private use, and one for visitors to use.  This way, if anything were to go wrong, i would still have a wireless connection, there just wouldn't be one for visitors for a while.  But now we're sharing a router, which is only half as bad, I guess (considering it's running dd-wrt)!

[Shane]

You can do it with 2 routers but you wont be able to share files with computers hooked to the first router from a computer hooked to the 2nd router.

Router B would get its WAN IP from router A and then router B would have a different local IP range.

Normally most people would just hook the 2nd router up to the modem and have it separate all together. This only works if your modem act as a router as well, otherwise most modems only give out 1 internet IP address which is why you cant just hook it up to the modem as well

Shane

[DanTheTechMan]

that's the exact setup I had.  the routers were in effect hooked together via the powerline adapter. router A's ip was .1.1 and router b's ip was .1.2

[Shane]

Yes but you have to make sure that router B had its connection from router A plugged into the WAN port and that you didnt have a static IP set for the WAN port yet.

Shane

[DanTheTechMan]

on which router?  i had a static ip for the connection from a to b.  is that where i went wrong?

[Shane]

You would have it like this

Modem --> Router A --> Router B

Cable from Modem is plugged into WAN port in Router A
Cable from Router A Is plugged into a LAN port and the other end that is plugged into Router B will be in the WAN port.

Router B should have the WAN IP set to auto get as it will get its WAN IP from Router A.

Thats all there should be to it, the LAN in router B will auto change when it sees the WAN IP it got and you now have 2 separate networks and both online.

If Router B has a static WAN IP it isnt getting connected because the IP it would get from Router A doesnt match and so it doesnt get online.

Shane

[DanTheTechMan]

Thanks a bunch! your help is greatly appreciated!

[Shane]

Always happy to help

Shane