[SOLVED] Connecting network printer via secondary ethernet card

Ruhpolding · 03-08-2015, 07:38 AM

There are two ethernet adapters on my system:

Code:

$lspci | grep Ethernet
00:13.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
00:0c.0 Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 30)

The first one is located on the main board and connects the router. The second one is a PCI card which will be connected to a Brother HL-5350DN network printer by a crossed ethernet cable.

Content of /etc/network/interfaces:

Code:

# Loopback
auto lo
iface lo inet loopback

# Router
auto eth0
iface eth0 inet dhcp

# Printer
auto eth1
iface eth1 inet static
      address 192.168.2.5
      netmask 255.255.255.0

Unfortunately, the host 192.168.2.5 acts just like a loopback device. Even when no cable is fitted into the eth1 adapter I get the following result:

Code:

$ ping 192.168.2.5
PING 192.168.2.5 (192.168.2.5) 56(84) bytes of data.
64 bytes from 192.168.2.5: icmp_req=1 ttl=64 time=0.041 ms
64 bytes from 192.168.2.5: icmp_req=2 ttl=64 time=0.041 ms
64 bytes from 192.168.2.5: icmp_req=3 ttl=64 time=0.039 ms

There is no traffic on the device eth1 indeed:

Code:

$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:41:86:85:81:0c  
          inet addr:192.168.1.2  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11197 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10582 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:9570615 (9.1 MiB)  TX bytes:1164352 (1.1 MiB)
          Interrupt:18 

eth1      Link encap:Ethernet  HWaddr 00:01:20:9a:c7:b2  
          inet addr:192.168.2.5  Bcast:192.168.2.255  Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:16 Base address:0xe000 

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:220 errors:0 dropped:0 overruns:0 frame:0
          TX packets:220 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:18316 (17.8 KiB)  TX bytes:18316 (17.8 KiB)

Please tell me, what is wrong with this configuration?

michaelk · 03-08-2015, 08:10 AM

Welcome to LinuxQuestions

Looks ok to me. Being able to ping yourself is normal.

Is the printer connected and its network configured? Can you ping the printer?

Ruhpolding · 03-08-2015, 03:03 PM

Thanks for your assessment.

It doesn't matter whether the cable is plugged in or not. This ping command runs always on the loopback. And other things like "telnet 192.168.2.5" or browsing http://192.168.2.5/ don't go out of the system either.

Nevertheless, the connection to the printer seems to work (full-duplex is detected). Only the ntpd daemon causes some traffic on the eth1 device, surprisingly.

With

Code:

ifup --no-scripts -v eth1
Configuring interface eth1=eth1 (inet)
ip addr add 192.168.2.5/255.255.255.0 broadcast 192.168.2.255 dev eth1 label eth1
ip link set dev eth1 up

the system console shows the following messages:

Code:

Mar  8 20:51:02 machine avahi-daemon[2453]: Joining mDNS multicast group on interface eth1.IPv4 with address 192.168.2.5.
Mar  8 20:51:02 machine kernel: [  517.796749] eth1:  setting full-duplex.
Mar  8 20:51:02 machine avahi-daemon[2453]: New relevant interface eth1.IPv4 for mDNS.
Mar  8 20:51:02 machine avahi-daemon[2453]: Registering new address record for 192.168.2.5 on eth1.IPv4.
Mar  8 20:51:03 machine avahi-daemon[2453]: Joining mDNS multicast group on interface eth1.IPv6 with address fe80::201:2df:fe9c:a7b2.
Mar  8 20:51:03 machine avahi-daemon[2453]: New relevant interface eth1.IPv6 for mDNS.
Mar  8 20:51:03 machine avahi-daemon[2453]: Registering new address record for fe80::201:2df:fe9c:a7b2 on eth1.*.
Mar  8 20:51:05 machine ntpd[3237]: Listen normally on 12 eth1 192.168.2.5 UDP 123
Mar  8 20:51:05 machine ntpd[3237]: Listen normally on 13 eth1 fe80::201:2df:fe9c:a7b2 UDP 123
Mar  8 20:51:05 machine ntpd[3237]: peers refreshed

michaelk · 03-08-2015, 06:22 PM

ntp is configured to listen on all interfaces. Not really a problem.

Ruhpolding · 03-09-2015, 12:18 PM

Now, I have managed to talk to the printer (via telnet and http). For this purpose, /etc/network/interfaces has been reduced to

Code:

# Loopback
auto lo
iface lo inet loopback

# Printer
auto eth1
iface eth1 inet static
        address 10.12.220.100
        netmask 255.255.255.0
        gateway 10.12.220.201

The printer is configured to have the IP address 10.12.220.201 (I got the information by printing the printer settings).

Unfortunately, this configuration does not include the internet connection any longer. Therefor I would have to append

Code:

# Router
auto eth0
iface eth0 inet dhcp

to /etc/network/interfaces. This implies that for eth0 a gateway is defined as well. However, more than one gateway is not allowed and complained by ifup(8) with the cryptic error message "RTNETLINK answers: File exists".

How can I create an entry for eth1 without including any gateway statement?

michaelk · 03-09-2015, 03:02 PM

Do not specify a gateway for eth1

Ruhpolding · 03-09-2015, 03:58 PM

Using at first two different private networks for the computer and the printer led into this dead end which I could leave now with your help. Many thanks!