Managing and using network connectivity on a Ubuntu system

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197
votes
20answers
393k views

Command for determining my public IP?

If I check with google, I can see my public IP. Is there something on the Ubuntu command-line which will yield me the same answer?
118
votes
6answers
27k views

Best way to cache apt downloads on a LAN?

I have multiple Ubuntu machines at home and a pretty slow internet connection, and sometimes multiple machines need to be updated at once (especially during new Ubuntu releases.) Is there a way where ...
117
votes
11answers
171k views

How to display network traffic in terminal

how to display the actual network traffic (wireless) in a terminal? Additionally: Is it possible to add this info to the chart of top?
104
votes
6answers
178k views

How to know what program is listening on a given port?

I suspect a program is listening on port 8000 on my machine. When I run the following command, I get that error: > python -m SimpleHTTPServer # Lots of python error socket.error: [Errno 98] ...
103
votes
14answers
480k views

How to restart the networking service?

I tried to use sudo service networking restart and sudo /etc/init.d/network restart but they both crash the window manager and I can no longer use my keyboard for input into X. when I use the ...
91
votes
10answers
150k views

How do I clear the DNS cache?

I just updated the DNS record (ns1, ns2, ns3.myhostingcompany.com) for a site I've got hosted, but I still get the domain registrar parking page. I'd like to see if the problem is Ubuntu's cached DNS ...
83
votes
5answers
36k views

How do I find out which process is eating up my bandwidth?

I think I'm being the victim of a bug here. Sometimes while I'm working (I still don't know why), my network traffic goes up to 200 KB/s and stays that way, even tough I'm not doing anything ...
63
votes
1answer
83k views

What is the loopback device and how do I use it?

What are loopback and localhost? Why do they exist, what are they used for, and how would I use them?
63
votes
0answers
87k views

How can I find my public IP using the terminal? [duplicate]

I am on DHCP, having dynamic IP. Finding your public IP when using a GUI and a browser is extremely easy. Simply go to Google.com and search for "What is my IP". Google will display it in the very ...
60
votes
4answers
101k views

What is the equivalent of the “tracert” DOS command?

tracert is a command in MS-DOS command prompt to trace the route to an IP Address. Is there any command in the Gnome Terminal equivalent to this?
59
votes
5answers
54k views

How do you test the network speed betwen two boxes?

I have gigabit network setup in my house and few Ubuntu based boxes. Out of complete curiosity I would like to check the speed between the two boxes. I am not having any problems with speed or ...
54
votes
4answers
49k views

Wireless networking not working after resume in Ubuntu 14.04

[Update]: The same problem exists in Kubuntu and is solved in the same manner. [Solved]: By applying the following command nmcli nm I got the following: Before suspend RUNNING STATE ...
52
votes
11answers
173k views

List all MAC addresses and their associated IP addresses in my local network (LAN)

How can I list all MAC addresses and their associated IP addresses of the machines connected to my local network (LAN)?
50
votes
4answers
211k views

How to successfully restart a network without reboot over SSH?

In Ubuntu 14.04 neither sudo service networking restart nor sudo /etc/init.d/networking restart do anything any more. They also both exit with code 1. Something has obviously changed (or half changed) ...
50
votes
1answer
99k views

How do I setup an Icecast server for broadcasting audio in my network?

Broadcasting the output of the soundcard as an internet radio stream is a reliable way to stream audio in a network. This can nicely be used to e.g. transmit audio in a wireless LAN to another ...
49
votes
3answers
40k views

How I can limit Download/Upload bandwidth?

How I can limit Download/Upload bandwidth for: Entire OS. One network interface. Single application.
48
votes
13answers
59k views

How can I capture network traffic of a single process?

I would like to examine the network traffic being handled by a single process, but simple network captures won't work since I am dealing with such a busy system (lots of other traffic happening at the ...
46
votes
7answers
154k views

How do I find my internal ip address?

I have ubuntu server 12.04 installed so I have no GUI. When I do the command ifconfig, I cannot find my internl ip address. it says inet addr: 127.0.0.1 . here is output of ifconfig -a: eth0 link ...
45
votes
6answers
175k views

How do I fix a “Wireless is disabled by hardware switch” error?

I just updated to Ubuntu 12.04 from 11.10 but soon after updating I was disappointed to see that Wireless is disabled by hardware switch. I can not click the button 'Enable wireless' which is ...
43
votes
3answers
62k views

How can I see what ports are open on my machine?

I would like to see what ports are open on my machine, e.g. what ports my machine is listening on. E.g. port 80 if I have installed a web server, and so on. Is there any command for this?
41
votes
6answers
120k views

“waiting for network configuration” Problem

This problem happens sometimes when ubuntu starts up. You can't really boot to the interface sometimes. Splash Screen with the 5 dots and a message saying: waiting for network configuration ...
41
votes
4answers
46k views

Network service discovery disabled: What does this mean for me?

Every time at boot I get a message “Network service discovery disabled. Your current network has a .local domain, which is not recommended and incompatible with the Avahi network service discovery. ...
39
votes
9answers
45k views

What's the best way to SSH to machines on the local network?

I have 2 computers, one that I use and one for the kids. I want to be able to ssh into their computer to control it (like to shut it down etc) but am curious the best way to do this. We both are in ...
38
votes
7answers
62k views

chat over lan from linux to linux?

As I recall there was something like netsend on windows that allowed simple messages to be sent over the local network. I especially like this because one doesn't need to install extra client soft ...
37
votes
10answers
81k views

What is the correct way to restart udev?

I've changed the name of my eth1 interface to eth0. How to ask udev now to re-read the config? service udev restart and udevadm control --reload-rules don't help. So is there any valid way ...
35
votes
5answers
11k views

Last upgrade crashes network manager (no internet connection, no applet)

While upgrading today, something caused my wireless network manager to disappear. Not even connecting via wired connection. This error is being shown by files: **(nm-applet:2716): WARNING **: Could ...
34
votes
2answers
21k views

connecting to archive.ubuntu.com takes too long

I have a Ubuntu 11.10 server that I just installed fresh. Now if I try to do anything with apt-get, it tries to connect to archive.ubuntu.com .. It stays at [Connecting to archive.ubuntu.com ...
32
votes
13answers
45k views

Nice network diagram editor?

Writing a commercial proposal, I want to create a nice graphic showing the clients the architecture I thought of for their IT network, with servers, network connections, firewall, load-balancing, etc. ...
32
votes
6answers
63k views

“Waiting for network configuration” adding 3 to 5 minutes to boot time

I get the following pieces of information at the startup, takes about 3 to 5 minutes, while normally about 1 minute: Waiting network configuration Booting system without full network configuration ...
31
votes
3answers
9k views

How to run a script, depending on internet connection

I often mount a remote drive using sshfs. I would love to have this mount automatically. However, if I mount it in my .bashrc or startup scripts, the mount often fails because my wireless internet ...
31
votes
6answers
96k views

How to see all computers connected to a network

I am in a LAN and there are 3 Ubuntu, 2 Kubuntu, 2 Windows XP and 2 Windows 7. What commands or tools are available to see what PCs are connected to the LAN that it shows the name of the PC and the ...
31
votes
2answers
12k views

Network disabled on some wake-ups on saucy laptop [closed]

Since I upgraded to Saucy Salamander 13.10, with every third suspend or so, the network is disabled and I'm unable to re-enable it. I've had to reboot to make it run again. The network menu will have ...
30
votes
3answers
43k views

How do I install dig?

How do I install dig? I can't figure out what the package name is.
30
votes
5answers
49k views

Can't connect to WPA2 Enterprise PEAP

My university uses WPA2 Enterprise encryption for students to login their wireless. In NetworkManager I have keyed in everything that they needed Security : WPA & WPA2 Enterprise Authentication ...
30
votes
3answers
47k views

How do I setup OpenVPN so I can securely use the internet from an unsecured hotspot?

Goal: I want to be able to securely use the internet via my home PC while my notebook is connected to an open hotspot/access point. I do know that I can use a SSH tunnel/SOCKS proxy, but I don't want ...
30
votes
4answers
12k views

How can you monitor internet download usage?

Some broadband providers impose a monthly download limit, charging extra if you go over. It is also quite easy to exceed some of the lower limits just by installing/updating packages and 'normal' ...
29
votes
7answers
1k views

What precautions should I take when exposing my desktop directly to the internet?

I've always used my Ubuntu desktop behind the security of a router with NAT, but there have been a few times when I've had to plug it directly into an active cable modem. In general, what precautions ...
29
votes
5answers
1k views

How can I reliably check which is the last time an Ubuntu machine has been connected to the internet?

How can I reliably check which is the last time an Ubuntu machine has been connected to the internet? In case this is not possible, a way to check the last time an Ubuntu machine has been connected ...
29
votes
3answers
15k views

bind software to different network interfaces

I have two different network interfaces, connected to 2 networks. One is an eth0 and the other one a wlan0. How can I tell a software to use only a specific interface? Basically I want Firefox to ...
28
votes
1answer
79k views

How do I add a network printer in Ubuntu 12.04?

I know the name and the IP address of a network printer, but I can't seem to be able to search by IP address or name. Ubuntu developers love to move things around to make it difficult for users, so ...
28
votes
3answers
18k views

What is the difference between Network Manager and 'ifconfig' 'ifup', etc?

Ubuntu seems to provide at least two network "toolsets" (for lack of a better term). I'm running into conflicts between these two. Network Manager Something which is more like the traditional ...
27
votes
4answers
78k views

How to find all the used IP addresses on a network

In my work there is a lot of computer and I want make a joke. I can close computer over the network but finding IP addresses is hard to me. How can I easily find all online IP adresses from ...
27
votes
2answers
114k views

How do I install drivers for the Atheros AR8161 Ethernet controller?

I have installed Ubuntu 12.04-64 bit on my Lenovo IdeaPad laptop, and the wired Ethernet (LAN) connection doesn't work. Running the lspci -vv | grep Atheros command from the terminal shows me I have ...
27
votes
2answers
48k views

How to share a wired internet connection via Wifi?

Can someone please help me with a complete step by step guide to share my internet connection (which is through a USB modem by ZTE) with my iphone 3G?
27
votes
4answers
24k views

What are the significant differences between tracepath and traceroute?

I recently read a bit of an article on HowToGeek that has me scratching my head a little. I've got fairly little experience with Linux though, so forgive me if this is entry-level: "The tracepath ...
26
votes
6answers
44k views

How do I renew my DHCP lease?

Short of rebooting, how can I release and renew my DHCP lease? It would be useful to know a GUI and terminal method. I'd especially like to know if there is a means to do this without requiring admin ...
26
votes
2answers
42k views

Is there LAN topology mapping software available in Ubuntu?

I need to do a graphical map of all the layer-2 and layer-3 machines running in my LAN. I don't want a graphical tool like Dia or similar, but a kind of "graphical Nmap" which shows the real cabling ...
26
votes
3answers
203k views

How to setup static IP in Ubuntu Server 12.04?

sudo apt-get update sudo apt-get upgrade ifconfig sudo nano /etc/network/interfaces auto eth0 iface eth0 inet static address 192.168.1.150 netmask 255.255.255.0 network 192.168.2.0 broadcast ...
25
votes
7answers
62k views

How to run “sudo apt-get update” through proxy in commandline?

In my office i want to update and download through (wget) and here they are using proxy? How can i do this by commandline?
25
votes
5answers
83k views

In VirtualBox, how do I set up host-only virtual machines that can access the Internet?

In setting up virtual machines with VirtualBox, I often want the following characteristics vm has a static ip host can access vm without port forwarding vm can access the internet I can move ...