Wired printer problems

[Brent1970]

Hey guys, I have a non-wireless printer connected to a switch which is connected to the switch on the back of a Comcast router. The PC is connected to the same router but via wireless. Now, the wireless was set to a different subnet so I could not get the PC to print to the printer. I logged on to the router and changed the wireless subnet to the same subnet that was on the switch on the back of the router.

So, the subnet coming out of the switch on the back of the Comcast router was 192.168.0.x and now the wireless subnet is also 192.168.0.x. The PC and the printer should now be on the same subnet, right? Well, I would have thought so but apparently it is considered two separate subnets because when I try to ping the printers IP from the PC I get destination host unreachable.

Is it because the subnets are coming out of two separate network interfaces even though its the same device?

I thought perhaps I could just get a small WAP and connect it via ethernet to the same switch the printer is on and then connect the PC wirelessly to that. Would that allow me to finally be on the same subnet?

(I realize running a network cable to the PC would also work but the person does not want that.)

 

[Elixer]

Um, exactly which comcast router is this?
Does your WAN port have a public IP address, or is it private (10.x or 192.x...)?

Assuming the WAN has a public IP address, you either enable DHCP server, and let it hand out IPs for both wired & wireless, or you can assign static IPs.

 

[Brent1970]

The Comcast router is a Cisco DPC3941B. It has 4 ethernet ports on the back of it and its dual band wireless.

It doesn't give me much information about the ethernet ports, tbh. No where can I find where it says what subnet it is but I know from plugging a switch into it that its 192.168.0.x. The DHCP server is active but seems to be using both subnets - handing out 192.168.0.x addresses if you plug into the ethernet ports on the back and 10.1.10.x addresses if you connect wirelessly.

The WAN IP is public.

-edit- This is a business router if that is relevant.

 

[boomerang]

I think you just need to reset the configuration on the printer at this point. If somebody set it to a static IP within the 10.X range, it's stuck there. You probably just need to find out how to reset it to the default settings.

How your computers will deal with a new IP on the printer will be your next task. Or, that may be your problem right now.

 

[Brent1970]

@Boomerang: No, I already configured the printer to get an auto-assigned IP which it did from the switch I have hooked up to an ethernet port on the back of the router.

Thats not the problem. The problem was the dual subnets - one subnet from the ethernet ports on the back of the router and a different subnet on wireless. The PC only connects via wireless so had a different subnet.

I'm hoping when I get this WAP in and hook it up to that same switch the printer is hooked up to I can have the PC connect wirelessly through it and be on the same subnet finally as the printer.

 

[Elixer]

The Comcast router is a Cisco DPC3941B. It has 4 ethernet ports on the back of it and its dual band wireless.

It doesn't give me much information about the ethernet ports, tbh. No where can I find where it says what subnet it is but I know from plugging a switch into it that its 192.168.0.x. The DHCP server is active but seems to be using both subnets - handing out 192.168.0.x addresses if you plug into the ethernet ports on the back and 10.1.10.x addresses if you connect wirelessly.

The WAN IP is public.

-edit- This is a business router if that is relevant.

Ahh, business router.
So, they set up 2 VLANs for you, which they tend to do for security reasons, and I am pretty sure you could disable that, but, I am not familiar enough with this device to tell you how.
I assume the router will have VLAN options someplace, there would be a good place to start looking on what you can do.
Heck, they might even have a option to bridge the gateway...
Then again, they might have disabled this as well, depends on how locked-down this unit it.

You could also tell them to put you in full bridge mode, then get a different router to handle everything the way you want.

 

[Brent1970]

@Elixer: On the "At a glance" page in the router it has a button to turn on Bridge mode but when I turn that on it immediately gives me a warning popup, to wit, "Enabling bridge mode will disable Router functionality of the Gateway and turn off private Wi-Fi network. Do you still want to enable bridge mode?". This seemed like a horrible set of circumstances so I cancelled out of it.

I have looked through literally every single option in the router and can find nothing about a VLAN. There is some option to turn on MoCA but I'm still unclear what that is.

Do I take it that you do not think adding a small WAP connected to the same switch the printer is on and then connecting the PC to that will allow them both to be on the same subnet?

 

[sdifox]

@Elixer: On the "At a glance" page in the router it has a button to turn on Bridge mode but when I turn that on it immediately gives me a warning popup, to wit, "Enabling bridge mode will disable Router functionality of the Gateway and turn off private Wi-Fi network. Do you still want to enable bridge mode?". This seemed like a horrible set of circumstances so I cancelled out of it.

I have looked through literally every single option in the router and can find nothing about a VLAN. There is some option to turn on MoCA but I'm still unclear what that is.

Do I take it that you do not think adding a small WAP connected to the same switch the printer is on and then connecting the PC to that will allow them both to be on the same subnet?

Turn on bridge mode is supposed to turn off router functionality. So the warning can be ignored in this case.

 

[Brent1970]

@sdifox: Would disabling "router functionality" just make the router a ..switch at that point? I guess I'm unclear about that. Plus disabling the Wi-Fi network doesn't seem like a good thing especially since I thought that was what it was supposed to be bridging from - the Wi-Fi network subnet and the ethernet ports on the back of the router subnet.

Really, all I actually want to know is will a WAP connected to the switch that the printer is on and then the PC connected to that make them both on the same subnet?

 

[sdifox]

@sdifox: Would disabling "router functionality" just make the router a ..switch at that point? I guess I'm unclear about that. Plus disabling the Wi-Fi network doesn't seem like a good thing especially since I thought that was what it was supposed to be bridging from - the Wi-Fi network subnet and the ethernet ports on the back of the router subnet.

Really, all I actually want to know is will a WAP connected to the switch that the printer is on and then the PC connected to that make them both on the same subnet?

Sorry brain fart. I thought this was a two device setup, but it is one box. So you need to find setting to assign the ethernet ports to use nat.

 

[sdifox]

Wait they are already behind nat thatvis why you get 192 ips on it. I shoukd not be posting while sleepy :d

 

[sdifox]

Printers should be on static or reserved dhcp anywau.

 

[Elixer]

Printers should be on static or reserved dhcp anywau.

Normally, yeah, but the issue here is, if the printer is hooked up via wired, it is using a different subnet than the wireless, so the wireless clients wouldn't be able to use the printer.

As for that warning popup, that is disappointing.
If there is no menu option to create a wifi bridge, then it seems your only choice here is to put the unit in bridge mode, and then buy a new router, that way you will have complete control of the network.

I suppose there is a chance that commycast has hidden menus available, and they may be able to set something up on their end.

 

[sdifox]

Normally, yeah, but the issue here is, if the printer is hooked up via wired, it is using a different subnet than the wireless, so the wireless clients wouldn't be able to use the printer.

As for that warning popup, that is disappointing.
If there is no menu option to create a wifi bridge, then it seems your only choice here is to put the unit in bridge mode, and then buy a new router, that way you will have complete control of the network.

I suppose there is a chance that commycast has hidden menus available, and they may be able to set something up on their end.

Check the manual or contact comcast on why it doesnt work.