Ubuntu Networking :: Loopback Interface Not On Startup?
Apr 20, 2010
I own an Ubuntu Server 9.04 on a remote dedicated server. Since a few days (?) the loopback interface is not 'up' on reboot : I only have eth0 (which works fine).Here is my /etc/networking/interfaces (did not change since server initialization):
# 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
I'm running Ubuntu 11.04 and I've been unable to access any type of Internet service besides web browsing. When I check on Network Tools, it's always set on Loopback Interface, regardless of whether I've just switched it to Ethernet Interface. I haven't been able to download system updates through Update Manager. I'm not very experienced with Ubuntu.
I have a client's linux server where someone added a script which sends spam mails from the server's local loopback address (127.0.0.1) all my seniors worked on it and couldn't trace the script on the server this issue was going for a week, now I have an idea to bring down the loopback interface of that particular server(ya, that was not a permanent solution but just had an idea), but my support manager told that it will bring the whole server down(so far as i have learn't loopback address is used only for testing the NIC card's functionality), is that really bring the server down.?. How ever i tried this using a test machine all the connections works fine even after i bring down the loopback interface. As my client's server is a production server i can't test it there without clear knowledge, can any one help me out whether will it bring down the server or will it cause any side effects on it(i know that you guys are experts so i am asking it here)?
I have a problem with my F13 and wired connections on my Acer TravelMate 2410. When I connect the inet cable it doesn't show it as connected. When I type ifconfig, it shows everything as it should. When I tried to bring up eth0 with ifup eth0, it said that the device is not managed by NetworkManager. I tried to restart nm with service network restart, but it gave this error:
I have configured LVS under RHEL5. I need to configure static route to my VIP. Now, I used the following command to add route but reboot OS will flush the route.
# route add -host 192.168.11.55 dev lo:0
how to add static route for certain network via /etc/sysconfig/network-scripts/route-<device-name>. But I did not found that for host.
The following are the output of command "ifconfig -a":
[Code]....
The interface "eth0", which is down, was not displayed, but loopback interface has been displayed. So, how can I make my application display all interfaces, including the interfaces which are down, but excluding the loopback interface?
I have a server with 3 interfaces. Only one of them comes up after boot tho (the one with the cable plugged in). When I start dhclient the others show up in ifconfig... Could it be just cause there is no cable plugged in them? Or then how do i bring them up automatically without having to issue dhclient myself after boot?
I run a webserver Apache2, php5, and MySQL. They are all set up correctly and I can access my website at [URL] I have, also installed, noip2 to update my IP address to no-ip.com for my domain name. Here's the problem: I can access my website through that domain name on other computers, both on internet and on the same network. But I cannot access it from my own computer (using the domain name instead of localhost). I need to be able to access the domain name on my computer because some pages on my website have been defined as the address to my domain name and not localhost. I cannot change this to localhost because if I do then people outside cannot work the webpages correctly. I had the same troubles on Windows before and I simply enabled loopback connections by typing in my private IP address along with the domain name into the Windows hosts file. I use version 10.04.
I'm setting up a loopback server for work related testing. I have a small program that needs to be executed through telnet from about 200 IP's on the same network. On the server, I have to set a static ip, enable telnet login, and place my 2 program files in the appropriate folders so it will run. I have been on this for 2-3 days and haven't got far.
My /etc/Network/interfaces file is this... Auto lo iface lo inet loopback
The rest of terminal is filled up with these, and it states that the file only has 32 characters. I don't know if this is a privilege issue or not. I've read several threads on telnet, and lots of arguments about ssh, but I can't run ssh, so I need to enable telnet. There is not a security issue. I run a private network where the only valuable resource would probably be the text file with my IP address on it. Its also accessed by people that have very limited networking knowledge and no linux knowledge...
So, Set static IP Setup telnet server... Any takers?
I'm using Wordpress on Apache localy to keep a diary (it's convenient because of the tags). When I'm connected to any network (be it wired or wireless) my Apache (and Wordpress, of course) works just fine. But as soon as I go offline, I can't access the web server neither through browser nor by telneting to the 80th port. Pinging localhost works just fine.Here is my ifconfig when offline and when online:Online:
Code: eth0 Link encap:Ethernet HWaddr 00:24:54:6f:07:aa UP BROADCAST MULTICAST MTU:1500 Metric:1
So I have an Ubuntu server setup but my modem from my ISP only has one ethernet port so I have to run my server behind a router. I have been able to get the sever viewable to everyone outside of my network but when someone is inside my network they have to view the server by the direct IP the web address doesnt work nor does the actual static IP. I believe this is something to do with my router not being able to loopback. It is a belkin N600 DB.
Why does the loopback interface has such a high mtu? I get it that it needs to work out even large packets, which is logical but why this specific number? I can set the MTU even higher with the ip link command, so it's not a limitation of the variable used.
I have two ethernet card on my computer, I want to make a TCP or UDP communication between these two cards, so I disable loopback: #ifconfig lo down. but with out loopback I can't even ping an eth from another one. how should I do? I want traffic to really pass eth cards.
So I just partitioned my hard-drive, one side with windows the other to set free for ubuntu. It all worked fine. I put in the liveCD of ubuntu 9.10 and installed on to the partition. However, I have a problem. When it boots up it asks me to either boot into linux 2.6 or windows 7. Windows 7 works fine, but when I boot into ubuntu, the loading screen comes up and then it doesn't seem to boot into GDM. It's all command-line interface. I've tried sudo apt-get update and upgrade, but it isn't connected to my network yet so I can't do that. What can I do?
I'm running a Source Dedicated Server on my Ubuntu laptop, and to connect to it via external IP from other computers in the network I need to enable loopback in my router.This was working fine, but then I disconnected my laptop for a few days, and when I came back the wireless stopped working on my Xbox. I reset the router to factory defaults, and then setup everything again. It was all working fine until I enabled loopback again and power cycled my router. Now every time I do that, the internet on Ubuntu stops working and the wireless on the Xbox stops working.
Edit: You can ignore this I guess. It seems I was actually DISABLING loopback by enabling that router option, which I guess caused this. Strange, because the first time enabling this option was the only way to get my external ip to work. Oh well, everything is fine now.
QUESTION: Where do I add "pppd nomagic" to stop analog modem loopback errors? (I am using Gnome PPP.)BACKGROUND INFO:I am using Ubuntu LTS 8.04 on a laptop and have an analog modem connected via USB serial cable. The 8.04 dialup and the analog modem work flawlessly.Modem disconnects when using Ubuntu LTS 10.04.1 Live USB:I am testing LTS 10.04.1 on a live USB drive that I purchased preinstalled from On-Disk.On the live USB drive, I am able to get a dialup connection with my ISP long enough to pull up a web page with the browser. However, the analog modem disconnects within minutes with exit codes 16 or 17.an pppd:16 The link was terminated by the modem hanging up.The PPP negotiation failed because serial loopback was detected.
I just had an ATT Uverse RG installed. However my Smoothwall router that previously worked fine with the ADSL SpeedStream is no longer accepting an address assignment DHCP ip address from this new gateway. (3800HGV-B)Any thoughts ideas or experience working with this hardware? ATT only supports Windows and Mac
New CentOS 5.4 system working fine. Sys admins came in and copied the hosts file from one of the servers down to my desktop and ever sincethen machine has been slow (progs take 10-20seconds to load). RunningGnome. Luckily I saved the old hosts file and copied it back and all is now well. But I'd like to understand why, particularly as I will need to change myhostname in the future.
As configured: /etc/hosts (yes my hostname is "dummyName" that I will need to change later) 127.0.0.1 dummyName localhost.localdomain localhost
I have been searching the forums for quite a while, to add extra Loopback adapter in Centos 5.1, but no success! Could you please suggest me the steps? in Windows, it is quite easy to add as many adapters as you want. wondering, if this is even possible in Linux? I have to run GNS3/Dynamips for router emulation and bind those Loopback adapters to virtual routers!
I have the same problem in Windows 7 and Ubuntu 10.04 where I can't record "what I hear" or "Stereo Mix" or "loopback", etc...I did not have this problem in previous versions of Windows (XP) and Ubuntu (9.04)...I hope this isn't because of MPAA/RIAA/DMCA/ACTA crapAudio Card as reported by alsamixer: SigmaTel STAC9200
I am trying to expand my Ubuntu partition into my Windows 7 C: drive, but the win7 partioner will not let me shrink it because of immovable files. Is there anyway for me to but an loopback device in the windows partion, and have Ubuntu boot with that as the root device?
I've got 4 or 5 of these TRENDnet USB network adapters ( TU-ET100c ) that I use frequently when I'm configuring firewalls or IPS devices for customers. I use them in combination with VirtualBox to test. They've always worked great until my new laptop I just got, and I put 10.04 on it. Previously I was on 9.x. Sometimes they will give a link light, other times not. And when they do the interface shows that it's up, but I can't get any traffic across the interface.
Today I upgraded from 10.10 to 11.04. After accidentally turning off the computer during the upgrade, booting into recovery mode, remounting the file system as writable and finishing the upgrade, it worked just fine.
However, I can no longer use any wireless networks. Wired ethernet works fine, but the wireless inteface won't even show up when I run ifconfig. When I first installed 10.10, it worked instantly and I was able to use it during installation.
I have an HP Compaq nx7300 laptop with a Broadcom BCM4311 network card.
I have extracted the WebCamStudio java application into a folder in my Fedora 13 x86_64 installation. I can run WebCamStudio with the command java -jar "WebcamStudio.jar".
I can successfully select sources and view preview etc. However, the bottom status line permanently states "no output". There is no vloopback device to select in Cheese, camstream, Skype, AMsn etc. Does anyone know how I can get the loopback device to work?
I have added my username to the group "video"
I only have /dev/video0 - should there be another module for the loopback device?
