Ubuntu Server, 2 Ethernet Devices, Same Gateway - Want to force internet traffic through 1 device (or at least allow it to work!)
- by Chris Drumgoole
I have a Ubuntu 10.04 Server with 2 ethernet devices, eth0 and eth1.
eth0 has a static IP of 192.168.1.210
eth1 has a static IP if 192.168.1.211
The DHCP server (which also serves as the internet gateway) sits at 192.168.1.1.
The issue I have right now is when I have both plugged in, I can connect to both IPs over SSH internally, but I can't connect to the internet from the server. If I unplug one of the devices (e.g. eth1), then it works, no problem. (Also, I get the same result when I run sudo ifconfig eth1 down).
Question, how can I configure it so that I can have both devices eth0 and eth1 play nice on the same network, but allow internet access as well? (I am open to either enforcing all inet traffic going through a single device, or through both, I'm flexible).
From my google searching, it seems I could have a unique (or not popular) problem, so haven't been able to find a solution. Is this something that people generally don't do? The reason I want to make use of both ethernet devices is because I want to run different local traffic services on on both to split the load, so to speak...
Thanks in advance.
UPDATE
Contents of /etc/network/interfaces:
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet dhcp
# The secondary network interface
#auto eth1
#iface eth1 inet dhcp
(Note: above, I commented out the last 2 lines because I thought that was causing issues... but it didn't solve it)
netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.1.0 192.168.1.1 255.255.255.0 UG 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
UPDATE 2
I made a change to the /etc/network/interfaces file as suggested by Kevin. Before I display the file contents and the route table, when I am logged into the server (through SSH), I can not ping an external server, so this is the same issue I was experiencing that led to me posting this question.
I ran a /etc/init.d/networking restart after making the file changes.
Contents of /etc/network/interfaces:
# The loopback network interface auto lo iface lo inet loopback
# The primary network interface
auto eth0 iface eth0 inet dhcp
address 192.168.1.210
netmask 255.255.255.0
gateway 192.168.1.1
# The secondary network interface
auto eth1 iface eth1 inet dhcp
address 192.168.1.211
netmask 255.255.255.0
ifconfig output
eth0 Link encap:Ethernet HWaddr 78:2b:cb:4c:02:7f
inet addr:192.168.1.210 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7a2b:cbff:fe4c:27f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6397 errors:0 dropped:0 overruns:0 frame:0
TX packets:683 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:538881 (538.8 KB) TX bytes:85597 (85.5 KB)
Interrupt:36 Memory:da000000-da012800
eth1 Link encap:Ethernet HWaddr 78:2b:cb:4c:02:80
inet addr:192.168.1.211 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7a2b:cbff:fe4c:280/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5799 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:484436 (484.4 KB) TX bytes:1184 (1.1 KB)
Interrupt:48 Memory:dc000000-dc012800
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:635 errors:0 dropped:0 overruns:0 frame:0
TX packets:635 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:38154 (38.1 KB) TX bytes:38154 (38.1 KB)
netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
