Working with WiFi and Copper, how can I use both on different subnets on same workstation?

My office system uses a copper connection on a private subnet which does not have connections through any wifi device. This has been advised on security grounds.

A printer for the workstation on this system is connected by usb but I have been asked by some staff if they can print using their mobile phones. This would be via wifi, not 4G.

The problem seems to be that the printer must be on the same subnet as the phones. I am trying to get my head around what options are available using both networking devices (wifi & nic) on one computer. Is anything like this possible or am I dreaming?
Budge

The problem with configuring your workstation as you’ve described and especially using DHCP for both networks is that each network will also configure a Default Gateway. If you remove all default gateways except for one, then you’ll generally be OK. If you have multiple default gateways, then it’s possible that any traffic through one default gateway may not return through the same default gateway and then you’ll experience failed packets and resends.

When you configure multiple networks on your workstation, each network should have its own NetworkID, it’s the part of your network address which is masked. If you don’t do this, again you’ll have dropped packets. Default setups on SOHO routers won’t always set you up properly, they’ll sometimes configure both networks with the same NetworkID.

For other WiFi devices on your network, your Access Point must allow devices to discover and connect to other machines in your network… Some Access Points especially those which are often used for public Hot Spots won’t allow this. Test using Ping, and by hostname if you intend to use hostnames in your connection settings.

Once you’ve sorted out and configured your workstation’s networking properly, you shouldn’t have any problems providing printer services over either network to any other remote device on your network… But you will need to install printer drivers on your remote devices and be configured to send print jobs to your workstation address using a working configuration including the workstation address, port and protocol.

If your workstation and printer are both turned on, print services should “just work” since CUPS is a standard part of setting up any kind of printer in Linux.

There can be special procedures for Canon printers, especially if it’s an older model that still supports a proprietary printer protocol.

BTW… If you can afford a printer with networking support, IMO it’s well worth the money because the setup is less complicated(fewer things that can go wrong) and works without a workstation needing to be on.

TSU

Connect the workstation to the Wifi network.
Allow remote access from that access to the printer.

But … This requires that the workstation is always on, whenever phone users are around.

IMHO A better solution is een networkprinter. Most office printers have a wifi and/or wired connection option. No matter whether the workstation is available or not even there, it will work for the others.

Perhaps consider putting the printer on the wifi subnet. The wired LAN hosts can still reach it via the router with an explicit IP address (or hostname if using local DNS) defined.

Knurpht, do mean the printers which broadcast their own WLAN? – mobile telephones can connect via WiFi direct to the printer – not via the WLAN Router – the printer is a WiFi Access Point …

  • Alternatively, there are printers with a Bluetooth interface …

Hi Tsu,
Sorry it took a while to get back to you but opensuse server was inaccessible and left me with a connection issue on Network Manager. Seems OK now.
I shall need to go through your post carefully but some quick additional information may help clarify my options forward
.
The only computer which is critical and the reason for my post is on a separate subnet and I can easily give it a fixed IP.

What I do not yet know is if the printer I have will work only with a wifi connection. As I understand it it must be plugged in somewhere and at present it is plugged into USB port in the subject computer. I could get a new network printer if that would be the best option and put it on another subnet which does have wifi access and do the work in the Sophos box but I would need some help with that.

Reiterating the point about security, which seems to have been ignored in suggestions by others, is that there shall be no wifi connections to the subject computer’s subnet.

All the subnets and their relevant services are created, managed and controlled by a Sophox box between the router and the wan. Almost everything can be controlled from this device which has capabilities well beyond my know how but with help I am sure I can set things up as you have indicated.

Downstream switching is through managed switches. These are Level 2+ not full Level 3 but do all I need in our case.

There is only one other problem; the subject computer runs windoze 10 which is required for the accounting systems. (Not my choice!)

Grateful for your further comments with this additional information when you have time.
Regards,
Budge.

I note the various suggestions, for which many thanks. I shall investigate the other options of how I may connect the printer using wifi. What is not clear is if it must have it’s own host computer or just have wifi connection.
Will look at options that are available.
Regards.

Yes… NetworkManager makes a “Connectivity Check” to http://conncheck.opensuse.org if it can’t reach there it assumes you’re behind a captive portal of some type.

You can disable the check by creating a file in “/etc/NetworkManager/conf.d/” named, for example, “50-disable-connectivity-check.conf” which has the following content:


[connectivity]
interval=0

If the printer supports “WiFi Direct”, it needs neither a host computer nor, a WLAN Router …

  • But, this is currently, AFAICS, mainly a feature for mobile telephones …

To close this thread I am pleased to report that the printer I am now using has wifi which is independent from the USB connection and so can run either connection as required. What caused me problems at the start was the built-in wizard which was not quite so clever when trying to install on two different networks, not helped by the windoze assumptions. I have it now, so many thanks to all for helping me clear my thoughts. Now I can go and sort out a couple of other printers needing the same attention.
Thanks again,
Budge.