Wifi/Internet goes south when I plug in Ethernet printer ??

[dozer]

hi guys,

Running a freankenpad T60p UXGA with an intel-video t60 board that RichK in SF put in for me. I get internet via wifi from the Century-Link supplied DSL-modem/wifi-router. I'm running XPsp3, and all is well.

So today I go to install an HP2840 color laser printer....but as soon as I plug the ethernet cable in, I lose internet! It appears that I'm losing the wifi connection itself, between T60 and router.

Note that the ethernet works fine. I can install the driver and talk to the printer.

I did check the 'bindings' in network properties, and set the wifi to be first...but it made no difference.

Anyone have an idea?

thanks!

Ricardo

[precip9]

My dad has a HP1100, a breadbox size laser. I've noticed that when doing network scans, it by default broadcasts an open network. Since it never caused a problem, I can't tell you whether it was ever on the same channel as my house network. But suppose yours is? Then you've installed a radio jammer.

A nice tool to detect networks: http://www.metageek.net/products/inssider/

[dozer]

precip, thanks for weighing in.

The printer is NOT wifi. It's ethernet....cable, yes?

When I plug the --ethernet cable-- into my T60p, I lose the wifi connection to my router.



Ricky

[precip9]

Sorry, I did not realize that your printer is an old piece that would not have built-in wifi.

I don't have a similar system to test. But, depending upon how desperate you are, consider this possible diagnosis/ solution:
1. The printer is acting as a DHCP server, or
2. The firmware in the printer expects the printer to be hooked to a router that runs DHCP. Your direct connection excites a bug in either the laptop or the printer that makes the laptop think it is preferentially connected to a wired network.
3. A quick and dirty solution would then be to connect the computer and the printer to some old router that, hopefully, does not excite the bug.

I have a network bug which is also strange, and for which there is a workaround:
1. A W7 computer in the basement is connected to the router through two hubs.
2. The hub nearest the computer has an Asus RT-AC66u router/access point, set up as an access point.
3. When the W7 computer is booted, the network adapter does not see the home network. Instead, it reports it is connected to an unidentified network.
4. The workaround is this. The network adapter on the W7 machine is disabled (right click, menu), and re-enabled. Then all is well; it identifies the network, and connectivity is restored. This is only necessary after a cold boot. Hibernate is OK.
5. Another basement computer, connected through a 3rd router, has no problem.

[RealBlackStuff]

When I plug the --ethernet cable-- into my T60p, I lose the wifi connection to my router.

You are supposed to plug the printer's ethernet cable into your router, which then assigns an IP to the printer.
You also must install the printer-driver on each PC/laptop that wants to print (either wireless, or via network).

[dozer]

RBS, thanks for checking in.

In regards to plugging the printer directly into the laptop...

I've been doing just that with my LaserJet 4MV for 10 yrs...works perfectly.

But this new-to-me 2840 'breaks' the wifi connection....or 'breaks' Windows from looking for internet over the wifi. One or the other.....although it looks more like the wifi connection itself is being broken.

Anyway, plugging the printer in directly worked fine when it was the LJ4MV.

The router is 30' away in another room. Not convenient to plug the printer in there.

I'd also note that it's been common (in my experience) to have printers hooked directly to PC's, and then used over the wifi by others.

i.e....this should work.

We just need to ID what's happening to XP when it's plugged in.

thanks again RBS

[ajkula66]

hi guys,

So today I go to install an HP2840 color laser printer....but as soon as I plug the ethernet cable in, I lose internet! It appears that I'm losing the wifi connection itself, between T60 and router.

Where does the Ethernet cable that you're plugging into the 8240 originate? In the DSL modem/router?

Do you have another cable feeding your wireless router from the same modem?

[dozer]

hello George!

I've been meaning to write you anyway....to let you know that your suggestion works a treat. Running the R60 without the bad batt eliminated all windows lockups. Thank you!

There is a dsl-modem/wifi-router box in the other room. No enet cables plugged into it.

There is my T60 laptop and an HP2840 color printer, here in office. There is a single crossover cable between t60 and hp. That's it. No other cables.

There are 1-2 other thinkpads running wifi...although this issue happens even when I'm the only one home.

Ricardo

[ajkula66]

If I understand you correctly:

a) Your T60 is running off of a wireless connection

b) You're connecting the laptop and printer directly via Ethernet cable.

My thoughts:

Your T60 is "expecting" a live network connection from the LAN port once you plug the printer in, and shuts the wireless off.

There should be a setting within Windows to address this. Don't know where it is off the top of my head.

Good luck.

[dozer]

yup...exactly my thinking as well.

In fact, I thought I'd remembered it correctly...the 'order' in the 'binding' part of the network-cards properties. Went there, moved wireless to top/first....but no difference. I am hoping someone will chime in with the correct place/item in windows...

[dr_st]

What you're trying to do is non-standard, awkward and not recommended.

The fact that it used to work, by some combination of luck and randomness, in the past, does not mean you should do it.

If you want to use the printer over Ethernet, attach it to the router.

If you want to attach the printer to a computer, do so via USB, and then share the printer over the network with the other clients.

[ajkula66]

What you're trying to do is non-standard, awkward and not recommended.

The fact that it used to work, by some combination of luck and randomness, in the past, does not mean you should do it.

If you want to use the printer over Ethernet, attach it to the router.

If you want to attach the printer to a computer, do so via USB, and then share the printer over the network with the other clients.

Very well put...

[precip9]

What you're trying to do is non-standard, awkward and not recommended.

The fact that it used to work, by some combination of luck and randomness, in the past, does not mean you should do it.

If you want to use the printer over Ethernet, attach it to the router.

If you want to attach the printer to a computer, do so via USB, and then share the printer over the network with the other clients.

Very well put...

It probably did work at one time. HP drivers tend to fail as the specs drift. We had to retire an HP 2200, a very nice 1200 dpi printer, when it decided it didn't want to print pdfs anymore.

Rather than condemn it as nonstandard, I would call it non-mainstream, and so first to fall by the wayside with lack of maintenance by HP.

[dr_st]

I don't think that the particular issue he's describing can be caused by HP drivers.

I agree that non-mainstream is, in principle, a more accurate term, since I do see why in some special cases this setup might be a good idea. However, in the majority of practical cases it isn't, and that's what I wanted to make very clear.

[twistero]

This sounds more like a network issue than a printer issue.

First, please verify whether you're actually disconnected from the wireless network. Connect to the wireless network as usual, plug in the printer, then go to the Network and Sharing Center, assuming you're using Windows 7. Do you see your wireless network under "View your active networks"?
If you're still using XP, then go to whichever Control Panel folder that has all your network adapters, and check whether your wireless adapter is in a connected state and has an IP address.

The reason I'm asking is because it's perfectly possible for you to be connected to both the wireless network and the printer's network at the same time, while not being able to access the internet, because Windows is confused by the two networks.

I am guessing that the printer has a DHCP server listening on its Ethernet interface; if not, you shouldn't have been able to access the printer without entering an IP address somewhere manually. I can think of 2 ways how this can interrupt your access to the internet:

1. The printer has the same IP address as your router, or and IP address in the same subnet as your router. This way, when your laptop receives a DHCP offer from the printer (which advertises the printer as the default gateway of the subnet), it now has 2 potential routes to the "same subnet", one through the Ethernet interface and one through the wireless interface. It decides to send all traffic through the Ethernet interface, which obviously have no access to the internet.

2. The printer's IP is not in the same subnet as your router. Your laptop receives DHCP-assigned IP address from both the wireless router and the printer, and thus have 2 different default gateways. When it wants to reach the internet, it has to decide which gateway to send the traffic to. It decides to send through the Ethernet interface.

As to how exactly your laptop decides which way to send internet traffic when there's two possible routes, it involves how Windows choose the "metric" of either network, which can depend on many factors, such as link speed.


Maybe your old printer has a different default IP address. Maybe it had a 100Mbit ethernet interface instead of a Gbit one. Come to think of it, you never said the old printer was networked; it could have been a USB or parallel port printer, which would not have this entire networking mess. Any little change can mean your old printer "just works" but the new one doesn't.

If you don't have some networking knowledge, connecting one computer to multiple networks is a Bad Idea TM.


So, how can you use the printer and access the internet at the same time?

The easiest way to make it work would be connecting the printer to your laptop via USB. Don't use the Ethernet interface if you don't have to.

Alternatively, connect the printer to your router instead. You will have to either 1. set up the printer to receive an IP address via DHCP instead of offering IP addresses to others, and give it a static lease in your router settings, or 2. set up the printer to use a static IP in your router's subnet, outside of the router's DHCP range. This way, all computers on the same network can access the printer.

If you insist on connecting the printer to your laptop via Ethernet, then set different static IP addresses on the laptop's and printer's Ethernet interfaces that are in a same subnet that's different from your router's subnet. You may have to play with the Default Gateway setting a bit.