Ubuntu Server IP address not listed in ifconfig

Question

I am not sure why the command "ifconfig" did not show my IP address, but I was still able to reach other hosts in the same network. It happens too many times to me and I did try to search but no luck to explain it. It actually does show up in "ip addr" command. These are my configuration for a static IP address, "ifconfig" and "ip addr"

This one is a ubuntu version 14.04 installed on physical server. jessie/sid (Linux openstack 3.19.0-56-generic #62~14.04.1-Ubuntu SMP Fri Mar 11 11:03:15 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux)

Thank you so much!

root@openstack:/home/stack# ip address list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 169.254.169.254/32 scope link lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br100 state UP group default qlen 1000
    link/ether 0c:c4:7a:76:1b:08 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::ec4:7aff:fe76:1b08/64 scope link 
       valid_lft forever preferred_lft forever
3: em2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:c4:7a:76:1b:09 brd ff:ff:ff:ff:ff:ff
4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether fa:26:3a:76:77:1c brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
5: br100: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 0c:c4:7a:76:1b:08 brd ff:ff:ff:ff:ff:ff
    inet 10.11.12.1/24 brd 10.11.12.255 scope global br100
       valid_lft forever preferred_lft forever
    inet 192.168.20.46/24 brd 192.168.20.255 scope global br100
       valid_lft forever preferred_lft forever
    inet 192.168.20.49/32 scope global br100
       valid_lft forever preferred_lft forever
    inet6 fe80::8c2f:b6ff:fe58:4b11/64 scope link 
       valid_lft forever preferred_lft forever
10: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br100 state UNKNOWN group default qlen 500
    link/ether fe:16:3e:88:1e:51 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc16:3eff:fe88:1e51/64 scope link 
       valid_lft forever preferred_lft forever
13: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br100 state UNKNOWN group default qlen 500
    link/ether fe:16:3e:b4:69:7e brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc16:3eff:feb4:697e/64 scope link 
       valid_lft forever preferred_lft forever
17: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br100 state UNKNOWN group default qlen 500
    link/ether fe:16:3e:b9:d7:4a brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc16:3eff:feb9:d74a/64 scope link 
       valid_lft forever preferred_lft forever




root@openstack:/home/stack# ifconfig
br100     Link encap:Ethernet  HWaddr 0c:c4:7a:76:1b:08  
          inet addr:10.11.12.1  Bcast:10.11.12.255  Mask:255.255.255.0
          inet6 addr: fe80::8c2f:b6ff:fe58:4b11/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:627132 errors:0 dropped:0 overruns:0 frame:0
          TX packets:522836 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:3074313781 (3.0 GB)  TX bytes:308312132 (308.3 MB)

em1       Link encap:Ethernet  HWaddr 0c:c4:7a:76:1b:08  
          inet6 addr: fe80::ec4:7aff:fe76:1b08/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2884361 errors:0 dropped:24125 overruns:0 frame:0
          TX packets:816202 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3881966559 (3.8 GB)  TX bytes:181453552 (181.4 MB)
          Memory:fb200000-fb27ffff 

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:45652477 errors:0 dropped:0 overruns:0 frame:0
          TX packets:45652477 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:30760291923 (30.7 GB)  TX bytes:30760291923 (30.7 GB)

virbr0    Link encap:Ethernet  HWaddr fa:26:3a:76:77:1c  
          inet addr:192.168.122.1  Bcast:192.168.122.255  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:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

vnet0     Link encap:Ethernet  HWaddr fe:16:3e:88:1e:51  
          inet6 addr: fe80::fc16:3eff:fe88:1e51/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:487 errors:0 dropped:0 overruns:0 frame:0
          TX packets:58390 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:63154 (63.1 KB)  TX bytes:4422625 (4.4 MB)

vnet1     Link encap:Ethernet  HWaddr fe:16:3e:b4:69:7e  
          inet6 addr: fe80::fc16:3eff:feb4:697e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:13333 errors:0 dropped:0 overruns:0 frame:0
          TX packets:63555 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:1042620 (1.0 MB)  TX bytes:29097792 (29.0 MB)

vnet2     Link encap:Ethernet  HWaddr fe:16:3e:35:95:a0  
          inet6 addr: fe80::fc16:3eff:fe35:95a0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5086 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5567 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:450420 (450.4 KB)  TX bytes:8912581 (8.9 MB)


root@openstack:/home/stack# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto em1
iface em1 inet static
    address 192.168.20.46
    netmask 255.255.255.0
    network 192.168.20.0
    broadcast 192.168.20.255
    gateway 192.168.20.1
    # dns-* options are implemented by the resolvconf package, if installed
    dns-nameservers 8.8.8.8

What problem are you having? Have you done investigation using Google, which finds pages like this http://ubuntuforums.org/showthread.php?t=2232263 ? What environment is this - home PC, virtual server (which kind), AWS, etc? — Tim, Apr 12 '16 at 02:43
I already said in my post: the command "ifconfig" did not show my ip address which was already configured statically, but I was still able to see it in "ip addr" command. I will add more info about the environment in the question, and I did a lot of Google search before asking this question. — Long, Apr 12 '16 at 02:49
Don't post screenshots of terminals like that. Copy-paste the output into the question and use the code formatting feature for it. Also your question and screenshots have contradictory information about the output of `ip addr`. Which is it? — kasperd, Apr 12 '16 at 10:06
@kasperd thanks for your suggestion. In my question I was asking about the output of "ifconfig", not "ip addr". I also posted the screenshot of "ip addr" just to emphasize the point that the correct IP address was set but did not show up in "ifconfig" command. — Long, Apr 12 '16 at 10:22
@Long Without knowing the actual output of `ip addr` we don't know how the interface is actually configured, and thus we cannot explain the output of `ifconfig` either. — kasperd, Apr 12 '16 at 10:25
PS: I also posted the text quote of all output for further references. — Long, Apr 12 '16 at 10:46

score -1 · Accepted Answer · edited Apr 13 '17 at 12:22

-1

ifconfig is deprecated. See this article for more information. The modern equivalent of ifconfig on its own is

ip address list

edited Apr 13 '17 at 12:22

Community

1

answered Apr 12 '16 at 02:53

Tim

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I see, so it's equivalent to "ip addr". I could not vote-up your answer as my reputation is below 15. If no one provides further explanation, I will make yours an an answer. Thanks – Long Apr 12 '16 at 02:58
This answer does not explain the output of `ip addr` given in the question. And the linked question is about cases where multiple addresses are assigned to the same interface. But in this question there is only one. – kasperd Apr 12 '16 at 10:08
I may not have answered exactly what the OP asked, but I've given them the information they need - that ifconfig is deprecated and I've provided the command they should use. – Tim Apr 12 '16 at 19:09

Ubuntu Server IP address not listed in ifconfig

1 Answers1