1

I'm running Ubuntu Server 16.04.4
After a lot of struggling I managed to configure both ethernet and wireless connections.

The content of /etc/network/interfaces file is this:

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# Ethernet network interface
allow-hotplug enp9s0
iface enp9s0 inet static
    address 192.168.1.150
    netmask 255.255.255.0
    gateway 192.168.1.1

# Wireless network interface
allow-hotplug wlp5s0b1
iface wlp5s0b1 inet static
    address 192.168.1.151
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 192.168.1.1
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

up route add default gw 192.168.1.1 dev wlp5s0b1

and in /etc/wpa_supplicant/wpa_supplicant.conf there is the output of:

wpa_passphrase "MY SSID" MY_PASSWORD | sudo tee /etc/wpa_supplicant/wpa_supplicant.conf

which is:

network={
    ssid="MY SSID"
    #psk="MY_PASSWORD_IN_CLEAR"
    psk=LONG_HEX_STRING
}

Now, ifconfig shows that:

enp9s0    Link encap:Ethernet  IndirizzoHW 00:24:54:ad:ac:b4  
          indirizzo inet:192.168.1.150  Bcast:192.168.1.255  Maschera:255.255.255.0
          indirizzo inet6: fe80::224:54ff:fead:acb4/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:435 errors:0 dropped:0 overruns:0 frame:0
          TX packets:195 errors:0 dropped:0 overruns:0 carrier:0
          collisioni:0 txqueuelen:1000 
          Byte RX:54426 (54.4 KB)  Byte TX:26620 (26.6 KB)
          Interrupt:18 

lo        Link encap:Loopback locale  
          indirizzo inet:127.0.0.1  Maschera:255.0.0.0
          indirizzo inet6: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:14256 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14256 errors:0 dropped:0 overruns:0 carrier:0
          collisioni:0 txqueuelen:1 
          Byte RX:1055216 (1.0 MB)  Byte TX:1055216 (1.0 MB)

wlp5s0b1  Link encap:Ethernet  IndirizzoHW 00:1b:b1:48:12:86  
          indirizzo inet:192.168.1.151  Bcast:192.168.1.255  Maschera:255.255.255.0
          indirizzo inet6: fe80::21b:b1ff:fe48:1286/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:695 errors:0 dropped:0 overruns:0 frame:0
          TX packets:30 errors:0 dropped:0 overruns:0 carrier:0
          collisioni:0 txqueuelen:1000 
          Byte RX:125974 (125.9 KB)  Byte TX:3316 (3.3 KB)

and the routing table is this:

tommy@ubuntu-server:~$ route -n
Tabella di routing IP del kernel
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 enp9s0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 enp9s0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 wlp5s0b1

If I ping with the ethernet cable connected, all works good.
But if I remove the ethernet cable and ping 8.8.8.8 it's not working.

Now my guess is that in the routing table is missing a line like this:

0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 wlp5s0b1

In fact, if I run:

sudo route add default gw 192.168.1.1 wlp5s0b1

then the routing table is:

tommy@ubuntu-server:~$ route -n
Tabella di routing IP del kernel
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 wlp5s0b1
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 enp9s0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 enp9s0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 wlp5s0b1

and ping 8.8.8.8 without the ethernet cable work just fine.

So my question is this: is there a way of keep permanent the route that I added?

I've already tried to write the command in the last line of the /etc/network/interfaces file, as you can see above, in many different ways:

  • up route add default gw 192.168.1.1
  • up route add default gw 192.168.1.1 wlp5s0b1
  • up route add default gw 192.168.1.1 dev wlp5s0b1
  • as above but with up ip route ...
  • as above but with post-up instead of up

but it's not working.
Am I missing the correct syntax or is there any other solution?
Thanks for your help!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.