Two Networks, One Printer...?

Question

Ok more Networking fun for me... I have two Wi-Fi routers I'm using at home. The main router, connected to my modem to serv that room with good Wi-Fi/local devices and an Ethernet cable from the main router to my sub router up stairs. My dilemma: I have a printer connected to one of the LAN ports on the main router. When I'm connected to sub router, I cant communicate with the printer that's on the main router. Is there something I can do to make this work? I need to keep the sub router as it's own network though (when in the main routers web access, I don't want to see devices connected to the sub router). If there is a way, I'd sure would appreciate knowing the path to the answers, Thanks.

Answer 1

turn off "DHCP server" on the sub router



then all devices on the network will get their local IP address from the main router

(likely problem is- the sub router has DHCP server turned on - so when you connect to it your computer gets its IP address from this router and this address is ignored by the main router. Result is you cannot connect to any device connected to the main router - i.e printer



cant see any reason you would want to have the sub router on its own network

not wanting to see the other devices connected to it dont make sense . Why would you want to look, and why would you care

just set up 2 different homegroups - those on one group, everything else on the other)

)

Answer 2

Quite something, I would not wish to have such situation upon me. We can only throw at you possible solutions.



Though the theoretics were quite clear to me or anyone else that has some technical training, the printing protocol does not support anything outside a subnet, without tweaking I hope. Then, #1, try DMZ punch through router filter, #2 specify IP directly; no auto-discovery nonsense, it worked in another situation I was in. #3 setup printing server on the main network.

Answer 3

Wow, some people lead complicated lives. I'm not even going to ask why you need to firewall one 1/2 of your house from the other, but lets assume there is a reason....



One way to do this will be to customise the Static Routing table in Windows. This instructs the system to route all traffic that for a certain IP range to use a different gateway. So on network 1, the default gateway is Router 1, leading to the internet. But you create a static routing entry, for the one IP address of the printer, and send that to Router 2, and it gets forwarded to the printer. The printer has Router 2 as it;s default gateway, so passes any packets back to machines on network 1.



https://www.howtogeek.com/howto/windows/adding-a-tcpip-route-to-the-windows-routing-table/



Doing this means that the printer is the only device on network 2 that can be seen, and only PCs that have the static route added can see even that.



I've had to use this to set up remote printers in branch offices which had both lease line connections and their own internet line. The PC default to internet, but have static routes addded to access the head office. From head office the servers have routes added to send data to the remote printers and workstations via the lease line router, not the main internet router.



Yes it gets complicated. Putting everything on the same subnet is simpler.

Answer 4

Simple. Router 2 just needs to act as a switch. Lan from Router 1 to Lan port on Router2 (not the WAN as your creating a second network). Disable DHCP server from Router 2. Of course configure the wireless ahead of time before turning off DHCP on Router 2.

Answer 5

Why do you have a second subnet provided by the second router? If you have done this simply to provide more Ethernet ports or a second WiFi network then you can configure the connection to create a single large subnet.



However, if you have used two routers to provide you with extra security for devices connected to the second router then there is not too much you can do.



Assuming you can manage with one large subnet and the routers are connected to each other by Ethernet. Disable the DHCP service in the second router and connect the cable from the main router to one of the PC/LAN ports on the second router leaving that second router's WAN port unused. You can also change the private address of the second router to be an unused address in the subnet from the main router so that you can configure this router from the primary network. This address should be outside the DHCP address range of the main router.



If you have any devices on the second router using static addresses, then you will need to reconfigure the addresses.



There is one thing you can investigate. In my case, I have my printer connected to a PC on my second network. When I am using my Chromebook it uses a facility called Google Print that interfaces with an extension to the Chrome browser on the PC that is hosting the printer. I believe the print is bounced off a Google server, but apart from knowing that it works, I am not sure of the details.



For my laptop, when I am using the main router network, I switch over to the other WiFi to use the printer. It's a bit slow, but it works.



I know these aren't ideal solutions, but it might give you some ideas if a single big subnet is not appropriate.



I hope this helps.

Answer 6

First, explain why your subnets need to remain separate, so that we may understand what your needs are. Also:

- Which IP ranges do R1 & R2 currently use?

- List the makes & models of your routers.



Most folks probably would have:

a. Connected R2 (router-2) to R1 via their LAN ports (I'm assuming you're using R2's Intranet/WAN port).



b. Assigned R2 a static IP from R1's IP range. (This would allow you to config R2 remotely at a later date.)



c. Turned off R2's DHCP function so that R1 controlled DHCP assignments.



This would put ALL of your devices into 1 subnet -- allowing your devices to see each other.

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If you stick with your 2 subnet design then you'll need to see if your routers allow you to configure static routes.

Answer 7

Try setting up the printer with a fixed IP address. This worked for me, but your setup may be different.