I have a problem. First of all, I wan to set up a server on Ubuntu 14.04. I have 2 interfaces: eth0 for dhcp server and eth1 for internet connection. But if I connect to two networks at the same time, there isn't internet on PC. So I have to choose between server and internet. That's terrible, can anyone tell me how to close this issue?
/etc/network/interfaces:
auto lo eth0 eth1
iface lo inet loopback
iface eth0 inet static
address 172.16.1.100
netmask 255.255.255.0
broadcast 172.16.1.255
gateway 172.16.1.254
sudo route outputs:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth1
192.168.0.0 * 255.255.255.0 U 1 0 0 eth1
UPD:
ifconfig outputs:
eth0 Link encap:Ethernet HWaddr 90:e6:ba:46:1d:50
inet6 addr: fe80::92e6:baff:fe46:1d50/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:1110 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:184287 (184.2 KB)
eth1 Link encap:Ethernet HWaddr 00:04:75:98:5f:da
inet addr:192.168.0.101 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::204:75ff:fe98:5fda/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14498 errors:0 dropped:0 overruns:2 frame:0
TX packets:13096 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9710708 (9.7 MB) TX bytes:1840400 (1.8 MB)
Interrupt:18 Base address:0x4c00
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:65536 Metric:1
RX packets:4398 errors:0 dropped:0 overruns:0 frame:0
TX packets:4398 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:527890 (527.8 KB) TX bytes:527890 (527.8 KB)
Best Answer
Configuring the output of
ifconfig
and the comments given to my first answer, I think that the problem is related to way you configure your NIC's in/etc/network/interfaces
.As you don't have any specific configuration for eth1 in
/etc/network/interfaces
, I suppose that your modem is giving to your server the IP info via DHCP. As per theroute
ouput, you get your default gateway pointing to the modem so to Internet.But on your
/etc/network/interfaces
file for the eth0 you have also a default gateway configured (statementgateway 172.16.1.254
).You cannot have two default gateway on a system. The assignment of the default gateway on eth1 disable the static configuration of eth0, reason why there is no IP for eth0 in the
ifconfig
output and why Internet works and the internal network no more.You will have to remove the line
gateway 172.16.1.254
and try again.By doing so, of course, if you have more than one subnet on the internal LAN you won't be able to reach them anymore. Unless you configure static route towards all of these subnets on your server :
you can add the
route
command in a script saved under/etc/network/if-up.d
to be run each time an interface goes up.