Questions tagged [networking]

Managing and using network connectivity on a Ubuntu system

Use this tag for general questions about network connectivity, such as:

  • configuring network interfaces
  • diagnosing network issues
  • establishing a network connection

Questions about networking between Ubuntu and a non-Ubuntu system are on-topic unless the issue is clearly on the non-Ubuntu side.

Most questions should also have one or more tag to identify the aspect or protocol that the question is about:

Do not use the tag if your question is specifically about a networked application and not about network configuration. For example:

  • How do I configure my Linux firewall to let FTP through?
  • How can I upload only files that are more recent than the remote version over FTP?
21598 questions
22 answers

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?
  • 8,319
  • 4
  • 16
  • 21
23 answers

How to display network traffic in the 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?
8 answers

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 this error: > python -m SimpleHTTPServer # Lots of python error socket.error: [Errno 98] Address already in use If I use another port (8000 is the…
  • 5,043
  • 3
  • 12
  • 5
43 answers

Installing Broadcom Wireless Drivers

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible. What are the steps to install Broadcom wireless drivers for a BCM43xx card? I'm a user with no advance…
18 answers

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 /etc/init.d/ method it complains saying that I should…
  • 4,422
  • 7
  • 27
  • 36
9 answers

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 internal IP address. It says inet addr: Here is the output of ifconfig -a: eth0 link encap:Ethernet HWaddr 00:06:4f:4a:66:f0 …
Cam Jones
  • 3,541
  • 10
  • 21
  • 26
6 answers

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 internet-related. This sometimes happens to me with the…
  • 9,666
  • 11
  • 40
  • 45
15 answers

How do I clear the DNS cache?

I just updated the DNS record (ns1, ns2, 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 records. Is there a way to clear Ubuntu's DNS…
  • 3,309
  • 3
  • 22
  • 21
10 answers

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?
  • 7,645
  • 15
  • 30
  • 36
8 answers

How do you test the network speed between two boxes?

I have a gigabit network set up in my house and a 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 anything, it really is just the geek in me that is…
Jacob Schoen
  • 4,725
  • 7
  • 26
  • 29
1 answer

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?
Eliah Kagan
  • 113,757
  • 52
  • 310
  • 478
12 answers

Wifi doesn't work after suspend after 16.04 upgrade

This particular version of the "doesn't work after suspend" came after upgrading to 16.04. It seems that the upgrade includes a Wicd applet (added to Metacity Classic Gnome task bar alongside regular network icon), but doesn't seem to work after a…
  • 2,095
  • 5
  • 15
  • 17
6 answers

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 only one of my machines needs to download the…
Ken Simon
  • 2,023
  • 2
  • 15
  • 10
3 answers

How do I install dig?

How do I install dig (the DNS lookup tool)? I can't figure out what the package name is.
Eric Johnson
  • 5,745
  • 6
  • 23
  • 22
8 answers

How do I SSH to machine A via B in one command?

I want to access a computer, say machine A which is based in my university's network. However, this computer is only accessible via the internal network of the university, so I can not use SSH to this computer from home directly. Here's what I do…
  • 1,662
  • 2
  • 13
  • 11
2 3
99 100