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Setting up static IP - Ubuntu server 16.04

Hi,

Trying to set static address on Ubuntu Server 16.04 running in VM on free ESXi 5.5 host. I am editing the configurations file, saving it properly but still can't see the address I've set when I run ifconfig... Strangely enough, I can SSH using either 192.168.40.112 (that I think was the IP I got from DHCP) or newly assigned address 192.168.40.202...

administrator@VSAL001:~$ ifconfig
ens32     Link encap:Ethernet  HWaddr 00:0c:29:a1:40:e8
         inet addr:192.168.40.112  Bcast:192.168.40.255  Mask:255.255.255.0
         inet6 addr: fe80::20c:29ff:fea1:40e8/64 Scope:Link
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:973184 errors:0 dropped:0 overruns:0 frame:0
         TX packets:18902 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:1000
         RX bytes:142418745 (142.4 MB)  TX bytes:1405471 (1.4 MB)

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:160 errors:0 dropped:0 overruns:0 frame:0
         TX packets:160 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:1
         RX bytes:11840 (11.8 KB)  TX bytes:11840 (11.8 KB)


administrator@VSAL001:~$ sudo nano /etc/network/interfaces

File /etc/network/interfaces is being edited (by root with nano 2.5.3, PID 3412)


# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback


# The primary network interface
auto ens32
iface ens32 inet static
       address 192.168.40.202
       netmask 255.255.255.0
       gateway 192.168.40.1

       dns-nameservers 192.168.40.20

service networking restart

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I've tried networking restart and rebooting the server but still the same... At one point ifconfig was listing only loobback interface so I even recreated VM from scratch and reinstalled Ubuntu... I also think at one point it was a message asking me to load some other version of interfaces that was saved as swp....

Can you please help me cleanup this mess?

ASKER CERTIFIED SOLUTION

Dan Craciun

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inseek

ASKER

Commenting source /etc/network/interfaces.d/ did the trick but what the consequences are? I have other Ubuntu server (identical virtual host configuration) that does not have this line commented.

Thanks.

Dan Craciun

ls -al /etc/network/interfaces.d/

See what's there.

inseek

ASKER

administrator@VSAL001:/$ ls -al /etc/network/interfaces.d/
total 8
drwxr-xr-x 2 root root 4096 Jan 24  2016 .
drwxr-xr-x 7 root root 4096 Jan 12 16:04 ..
administrator@VSAL001:/$

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Dan Craciun

Well, that's weird. If the folder is empty, then source /etc/network/interfaces.d/* should of done nothing...

Can you monitor that folder to see if anything drops a files inside and then deletes it?

Something like
inotifywait /etc/network/interfaces.d --recursive --monitor
inside a screen

inseek

ASKER

OK, i've installed the program and executed

administrator@FUS212VSAL001:/$ inotifywait /etc/network/interfaces.d --recursive --monitor
Setting up watches.  Beware: since -r was given, this may take a while!
Watches established.

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Now what?

Dan Craciun

Now you wait to see if something shows up in that folder. Detach from the screen and check it again tomorrow.

Or uncomment that line in /etc/network/interfaces, restart networking and see what happens.

arnold

It is unclear what the issue is that you are seeing.
The ip on the system is 192.168.40.112
If you are not identifying systems uniquely, ssh to 192.168.40.202 you are ending up on a separate system.

What are the IPs of the ESX host?
try this, using two ssh shells connect one to 192.168.40.112 while the other to 192.168.40.202 and see if both sessions are on the same VM. Check the esx host config on whether you have a rule there that reroutes 192.168.40.202 to ... the VM in the event both end up on the same VM.

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ASKER

@ arnold

This Ubuntu server is the only Linux server on this vHost. Once I commented source /etc/network/interfaces.d/ I no longer can ping 192.168.40.112. I am pretty sure that both SSH sessions were to the same Linux VM so somehow both IPs are associated with the same network card. I have no special routing in place on the host that I've set myself just few days ago. I am also pretty sure we do not have any address reservations on our Windows DHCP server that is handling IPs to 192.168.40.0/24 network.

arnold

what is the output of ifconfig -a

your prior output points to 192.168.40.112.

there is no reference to 192.168.40.202.

there is no reason your system will respond unless it has the IP..

check whether you have configurations that have explicit bindings, but the system would have to reflect the IP.
....

Dillyn Barber

On my production server I added my IPs as such:

sudo nano /etc/network/interfaces

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and at the end of the file add lines for each IP like this:

        up ip address add 68.67.68.195 dev ens32
        up ip address add 68.67.68.196 dev ens32
        up ip address add 68.67.68.197 dev ens32
        up ip address add 68.67.68.198 dev ens32

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Ubuntu has made a lot of changes with how it handles networking since the release of systemd (and many more changes with systemd itself) so in 16.04 and up this is how you do it now. Expect every release to have some other annoying command/structure changes.

inseek

ASKER

I've un-commented that line in /etc/network/interfaces, restarted networking and now everything is fine. Thanks!