Otdfbt

If I no longer control a permanent when it would be sacrificed, is it still sacrificed?

How did the Apollo guidance computer handle parity bit errors?

Primes in a Diamond

What does のそ mean on this picture?

What does the copyright in a dissertation protect exactly?

How to speed up large double sums in a table?

Can an Iranian citizen enter the USA on a Dutch passport?

How to replace space with '+' symbol in a triangular array?

What is a precise issue with allowing getters?

How long does it take a postcard to get from USA to Germany?

Python 3 - simple temperature program version 1.3

Game artist computer workstation set-up – is this overkill?

Huffman Code in C++

Why are condenser mics so much more expensive than dynamics?

How to detect nM levels of Copper(I) Oxide in blood?

Installing Debian 10, upgrade to stable later?

TIP120 Transistor + Solenoid Failing Randomly

While drilling into kitchen wall, hit a wire - any advice?

Why would a military not separate its forces into different branches?

Guess the number game (Python)

Who filmed the Apollo 11 trans-lunar injection?

Is there precedent or are there procedures for a US president refusing to concede to an electoral defeat?

Debian 9 server no sshd in auth.log

How can I finally understand the confusing modal verb "мочь"?

No network loopback device after security update ubuntu 12.04

Server can't ping or connect to selfLoopback Device Not Configured On BootNetwork loopback device missing in Ubuntu 14.04Bringing up network interface without IP configured in Debian, for XEN dom0Configure static IPv6 on UbuntuHow to setup network interface to have eth0 as dhcp and eth0:1 as static ip?Static virtual IP in debian 6.0.4Writing to /etc/networking/interfaces at boot using sed/awk?Bridging Adapter in Ubuntu 12.04 LTS for KVMdisable a network interface on booting ubuntuIpv6 over bridged network stops working after some time (Ubuntu LXC)Need to enter a dhclient at every restart at UbuntuHow to correctly set up routing on machine with 4 interfaces so that three of interfaces are on the same subnet?

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty height:90px;width:728px;box-sizing:border-box;

6

2

I've had Ubuntu 12.04 on a server for the last several months, with everything working fine. Last night I did an aptitude update && aptitude safe-upgrade to bring in all the latest security changes, and now when I boot the server no lo device is created.

It brings up the physical ethernet interfaces correctly, and I can ping in and out of the machine on those interfaces, but nothing can connect to anything on either localhost or 127.0.0.1.

ifconfig lists only eth0 and eth1.

No lo at all.

Here are the contents of /etc/network/interfaces:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#NetworkManager#iface eth0 inet dhcp

Where should I be looking to diagnose and fix?

Thanks!

ubuntu networking ubuntu-12.04 interface loopback

share|improve this question

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  ...me too on 12.04.2. Machine boots fine, but no 'lo' shown by ifconfig. "ifup lo" brings it right up and then all is well (after stop/start of some servers that weren't happy without lo at boot.) You ever figure this out?
  
  – Craig Constantine
  Feb 25 '13 at 16:33
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please check your /etc/hosts. serverfault.com/questions/333269/…
  
  – Tinti
  Sep 3 '13 at 12:42
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @quangdog I am pretty sure this has been long resolved/forgotten but in a slight chance it has not been: what is the output of ifconfig -a on this machine?
  
  – Greg Dubicki
  Mar 1 '15 at 8:33
  
  

  
  
  
  

add a comment | 

6

2

I've had Ubuntu 12.04 on a server for the last several months, with everything working fine. Last night I did an aptitude update && aptitude safe-upgrade to bring in all the latest security changes, and now when I boot the server no lo device is created.

It brings up the physical ethernet interfaces correctly, and I can ping in and out of the machine on those interfaces, but nothing can connect to anything on either localhost or 127.0.0.1.

ifconfig lists only eth0 and eth1.

No lo at all.

Here are the contents of /etc/network/interfaces:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#NetworkManager#iface eth0 inet dhcp

Where should I be looking to diagnose and fix?

Thanks!

ubuntu networking ubuntu-12.04 interface loopback

share|improve this question

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  ...me too on 12.04.2. Machine boots fine, but no 'lo' shown by ifconfig. "ifup lo" brings it right up and then all is well (after stop/start of some servers that weren't happy without lo at boot.) You ever figure this out?
  
  – Craig Constantine
  Feb 25 '13 at 16:33
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please check your /etc/hosts. serverfault.com/questions/333269/…
  
  – Tinti
  Sep 3 '13 at 12:42
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @quangdog I am pretty sure this has been long resolved/forgotten but in a slight chance it has not been: what is the output of ifconfig -a on this machine?
  
  – Greg Dubicki
  Mar 1 '15 at 8:33
  
  

  
  
  
  

add a comment | 

I've had Ubuntu 12.04 on a server for the last several months, with everything working fine. Last night I did an aptitude update && aptitude safe-upgrade to bring in all the latest security changes, and now when I boot the server no lo device is created.

It brings up the physical ethernet interfaces correctly, and I can ping in and out of the machine on those interfaces, but nothing can connect to anything on either localhost or 127.0.0.1.

ifconfig lists only eth0 and eth1.

No lo at all.

Here are the contents of /etc/network/interfaces:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#NetworkManager#iface eth0 inet dhcp

Where should I be looking to diagnose and fix?

Thanks!

ubuntu networking ubuntu-12.04 interface loopback

share|improve this question

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#NetworkManager#iface eth0 inet dhcp

share|improve this question

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

share|improve this question

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

edited Mar 1 '15 at 9:23

Greg Dubicki

5851726

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

asked Oct 29 '12 at 20:57

quangdogquangdog

3112

2 Answers
2

active

oldest

votes

2

I have had similar problem.

My lo didn't start automatically at boot (after turning off IPv6 via sysctl and rebooting the server).

My first workaround was to start it manually with ifup --force lo. But after that I had to restart most of my services as they didn't work properly without loopback.

Finally this old forum post helped me to find out the proper and permanent solution:

1. sudo rm -rf /var/run/network/*


2. sudo reboot

(Apparently there was some old .lock file there that prevented the loopback to start properly.)

share|improve this answer

edited Jun 3 '17 at 16:36

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Note that ifconfig is deprecated. Use ip addr show instead.
  
  – the-wabbit
  Mar 1 '15 at 8:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  nice find! never would have thought to look in there.
  
  – killthrush
  Jun 23 '15 at 15:30
  

  
  
  
  

add a comment | 

0

If lo can be brought up manually with ifup lo but isn't brought up automatically, you should be able to put the command ifup lo in /etc/rc.local so it will start at each boot. Not an elegant solution but it should be a permanent solution.

share|improve this answer

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Doesn't work for me. Also tried with --force (which works on interactive shell) but to no avail.
  
  – Greg Dubicki
  May 1 '15 at 17:36
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "2"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fserverfault.com%2fquestions%2f443491%2fno-network-loopback-device-after-security-update-ubuntu-12-04%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

2

I have had similar problem.

My lo didn't start automatically at boot (after turning off IPv6 via sysctl and rebooting the server).

My first workaround was to start it manually with ifup --force lo. But after that I had to restart most of my services as they didn't work properly without loopback.

Finally this old forum post helped me to find out the proper and permanent solution:

1. sudo rm -rf /var/run/network/*


2. sudo reboot

(Apparently there was some old .lock file there that prevented the loopback to start properly.)

share|improve this answer

edited Jun 3 '17 at 16:36

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Note that ifconfig is deprecated. Use ip addr show instead.
  
  – the-wabbit
  Mar 1 '15 at 8:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  nice find! never would have thought to look in there.
  
  – killthrush
  Jun 23 '15 at 15:30
  

  
  
  
  

add a comment | 

2

I have had similar problem.

My lo didn't start automatically at boot (after turning off IPv6 via sysctl and rebooting the server).

My first workaround was to start it manually with ifup --force lo. But after that I had to restart most of my services as they didn't work properly without loopback.

Finally this old forum post helped me to find out the proper and permanent solution:

1. sudo rm -rf /var/run/network/*


2. sudo reboot

(Apparently there was some old .lock file there that prevented the loopback to start properly.)

share|improve this answer

edited Jun 3 '17 at 16:36

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Note that ifconfig is deprecated. Use ip addr show instead.
  
  – the-wabbit
  Mar 1 '15 at 8:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  nice find! never would have thought to look in there.
  
  – killthrush
  Jun 23 '15 at 15:30
  

  
  
  
  

add a comment | 

I have had similar problem.

My lo didn't start automatically at boot (after turning off IPv6 via sysctl and rebooting the server).

My first workaround was to start it manually with ifup --force lo. But after that I had to restart most of my services as they didn't work properly without loopback.

Finally this old forum post helped me to find out the proper and permanent solution:

1. sudo rm -rf /var/run/network/*


2. sudo reboot

(Apparently there was some old .lock file there that prevented the loopback to start properly.)

share|improve this answer

edited Jun 3 '17 at 16:36

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

share|improve this answer

edited Jun 3 '17 at 16:36

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

answered Mar 1 '15 at 8:32

Greg DubickiGreg Dubicki

5851726

0

If lo can be brought up manually with ifup lo but isn't brought up automatically, you should be able to put the command ifup lo in /etc/rc.local so it will start at each boot. Not an elegant solution but it should be a permanent solution.

share|improve this answer

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Doesn't work for me. Also tried with --force (which works on interactive shell) but to no avail.
  
  – Greg Dubicki
  May 1 '15 at 17:36
  

  
  
  
  

add a comment | 

0

If lo can be brought up manually with ifup lo but isn't brought up automatically, you should be able to put the command ifup lo in /etc/rc.local so it will start at each boot. Not an elegant solution but it should be a permanent solution.

share|improve this answer

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Doesn't work for me. Also tried with --force (which works on interactive shell) but to no avail.
  
  – Greg Dubicki
  May 1 '15 at 17:36
  

  
  
  
  

add a comment | 

If lo can be brought up manually with ifup lo but isn't brought up automatically, you should be able to put the command ifup lo in /etc/rc.local so it will start at each boot. Not an elegant solution but it should be a permanent solution.

share|improve this answer

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

share|improve this answer

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817

answered Mar 1 '13 at 18:30

bjschaferbjschafer

4817