Cable network printing stops when wireless is on

[michel]

Greetings,

After a full day of trial and error I just realized that when my wireless interface is connected to the wireless network, I cannot access the Xerox Phaser 7400DN printer on my Ethernet cable network.

I did not have this problem when I was using Mepis. The wireless network ip range is from 192.168.1.64 to 192.168.1.250 and the etho Ethernet cable connection is fixed at my end 192.168.123.21 and the printer at 192.168.123.251. Both networks have the 255.255.255.0 sub net Any clues?

Thanks,

Michel

[SteveRiley]

Your wireless subnet is 192.168.1/24 and your wired subnet is 192.168.123/24. These are different networks and you won't be able to communicate between them without some kind of router. You could:

* Use IP addresses in the range 192.168.1.1 - 192.168.1.63 for wired nodes
* Change your subnet mask to /16 (that is, to 255.255.0.0)

[michel]

The wireless modem, the printer and my computer are connected to the same switch via Ethernet cables. Why was this setup working with Mepis?

Thanks,

Michel

[SteveRiley]

The logical network (defined by subnets) can be completely distinct from the physical network. Given what you described above, you have two separate logical IP subnets. Datagrams can move across subnets only with the assistance of a router.

My suspicion is that your Mepis install enabled some kind of routing protocol (occasionally mistakenly called "bridging") between the two network interfaces. I can't confirm this because I've never used Mepis. Distros based on Debian, such as Ubuntu and Kubuntu, do not normally enable routing by default.

Also, please understand that my answer is based only on the information you've provided so far. Without more details, it's difficult to explain further. Does your computer have both a wired and a wireless interface? If so, do you enable both at the same time? If wired is enabled, and then you enable wireless while leaving the wired connection attached, does printing suddenly stop? How are your existing routers and switches configured?

If you could sketch something on a piece of paper and then post a photo, that would help. Label each subnet and interface appropriately. I apologize if this seems like a lot of work. Again, I'm not familiar with Mepis, so I can't predict what it might be doing. But I also can't give you more advice without knowing further details about your setup.

[michel]

I appreciate your assistance. Mepis is also based on Debian, so maybe a bridge was activated.

Yes if I deactivate the wireless connection on my Kubuntu notebook, I can see and connect to the printer normally. If the wireless connection is on, then I get "Printer is unreachable at this time".

I have attached a diagram of my network. Please let me know if you need more details.

Michel

[SteveRiley]

OK, so your network is a bit different than I first imagined. Thanks for the diagram, very helpful.

My first suspicion is that when you enable your wireless interface, it is somehow receiving a more preferred metric. Let's have a look at your routing table. Run the following two commands twice, first with the wireless disabled, and then with the wireless enabled.

ifconfig
route -en

[michel]

This is what I get

With wireless on:

michel@michel-Satellite-L650:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:26:6c:62:96:a3  
          inet addr:192.168.123.23  Bcast:192.168.123.255  Mask:255.255.255.0
          inet6 addr: fe80::226:6cff:fe62:96a3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10544 errors:0 dropped:300 overruns:0 frame:0
          TX packets:43710 errors:0 dropped:0 overruns:0 carrier:1
          collisions:0 txqueuelen:1000 
          RX bytes:1580416 (1.5 MB)  TX bytes:18366641 (18.3 MB)
          Interrupt:45 

eth1      Link encap:Ethernet  HWaddr b4:82:fe:e5:91:3d  
          inet addr:192.168.1.73  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::b682:feff:fee5:913d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4120061 errors:0 dropped:0 overruns:0 frame:7825815
          TX packets:4317978 errors:640 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3422351005 (3.4 GB)  TX bytes:836429096 (836.4 MB)
          Interrupt:17 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:924962 errors:0 dropped:0 overruns:0 frame:0
          TX packets:924962 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:62738336 (62.7 MB)  TX bytes:62738336 (62.7 MB)

michel@michel-Satellite-L650:~$ route -en
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         192.168.1.254   0.0.0.0         UG        0 0          0 eth1
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth1
192.168.123.0   0.0.0.0         255.255.255.0   U         0 0          0 eth1
192.168.123.0   0.0.0.0         255.255.255.0   U         0 0          0 eth0

With wireless off:

michel@michel-Satellite-L650:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:26:6c:62:96:a3  
          inet addr:192.168.123.23  Bcast:192.168.123.255  Mask:255.255.255.0
          inet6 addr: fe80::226:6cff:fe62:96a3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10544 errors:0 dropped:300 overruns:0 frame:0
          TX packets:43756 errors:0 dropped:0 overruns:0 carrier:1
          collisions:0 txqueuelen:1000 
          RX bytes:1580416 (1.5 MB)  TX bytes:18377949 (18.3 MB)
          Interrupt:45 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:925185 errors:0 dropped:0 overruns:0 frame:0
          TX packets:925185 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:62753704 (62.7 MB)  TX bytes:62753704 (62.7 MB)

michel@michel-Satellite-L650:~$ route -en
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth0
192.168.123.0   0.0.0.0         255.255.255.0   U         0 0          0 eth0

Michel

[SteveRiley]

Rats. Missing the metric...gave you the wrong flag. Please run

route -n

both with and without wireless. (The "e" is omitted this time.)

[michel]

No problem.

With wireless:

michel@michel-Satellite-L650:~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.254   0.0.0.0         UG    0      0        0 eth1
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U     2      0        0 eth1
192.168.123.0   0.0.0.0         255.255.255.0   U     0      0        0 eth1
192.168.123.0   0.0.0.0         255.255.255.0   U     1      0        0 eth0

Without wireless:

michel@michel-Satellite-L650:~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
192.168.123.0   0.0.0.0         255.255.255.0   U     1      0        0 eth0

[SteveRiley]

With wireless enabled, if you run

sudo route del -net 192.168.123.0 netmask 255.255.255.0 dev eth1

are you then able to access the printer? I presume you're only using the IP address when you try to communicate with the printer, not a hostname.

[michel]

I use it to communicate with the MAc through the switch. the Mac does not have a wireless adapter, it connects to the internet through the cable to wireless connection and with my Kubuntu notebook through a fixed IP Ethernet cable connection.

Should I still run the command?

Michel

[SteveRiley]

Ah, I wasn't really paying attention to the Mac. I see you're dual-homing it, too.

I think we should take a step back here and reconsider your network architecture, I would recommend simplifying it so that you're using only a single subnet and not have to worry about configuring routing. I realize that what you have "just worked" with Mepis, but I suspect that there's probably a more elegant way to design your network.

I presume the device labeled "wireless" also manages your connection to the Internet, correct? If so, then with a slight redesign and renumbering, we can make some improvements. But before I suggest anything, it would be good to have an answer to my question.

[michel]

Yes wireless is a DSL wireless modem.

Michel

[SteveRiley]

I would recommend you simplify your network as diagrammed in the attachment. There's really no need to dual-home the Mac or try to get routing running on your Kubuntu machine. My suggested changes:

• Use a single subnet, 192.168.1/24 ("/24" means subnet mask 255.255.255.0)
• Configure the LAN side IP address of your wireless router to 192.168.1.1/24
• Set the DCHP range to begin with 192.168.1.128 and end with 192.168.1.254
• Connect the switch to the router
• Connect the Ethernet port on the printer to the switch, use the static address 192.168.1.11/24
• Connect one Ethernet port on the Mac to the switch, use the static address 192.168.1.12/24
• Don't use the other Ethernet port on the Mac
• Connect the Ethernet port on the Kubuntu box to the switch, use the static address 192.168.1.13/24
• Configure the wireless interface on the Kubuntu box to use DHCP

Both computers will see the printer, the computers will see each other, and the Kubuntu box can easily move between wired and wireless.

[michel]

Thanks Steve,

I made all the changes and I ended up without any internet connection and I could not connect the Mac to the Kubuntu notebook AND the printer problem was not solved.

I returned the network to it's previous status AND I rebooted the Mac and Kubuntu WHILE the printer was on and guess what? Now I can print WITH the wireless on on the Kubuntu notebook!!!

I had tried your setup earlier on without changing IPs to the same 192.168.1 network and I got the same result with no internet on the Mac. Setting the wireless router to anything but 192.168.1.254 will always result in loss of internet connection.

While I would very much like to know why, I will keep things as is because if it ain broke, don't fix it!

Thanks,

Michel