A computer network allows sharing of resources and information among interconnected devices.
7
votes
4answers
9k views
How to make a machine accessible from the LAN using its hostname
Here are details of the machine I want to access using its hostname:
$ hostname
hostname
$ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 hostname.company.local hostname
It's a default Debian 6 ...
5
votes
3answers
2k views
Can't access select https sites on Linux over PPPoE
My internet connection used to be a direct LAN connection to my provider. Back then, everything would load fine on both Windows and Ubuntu (dual boot). However, a while ago they started needing me to ...
6
votes
2answers
5k views
Output traffic on different interfaces based on destination port
My question is basically the same as Only allow certain outbound traffic on certain interfaces.
I have two interfaces eth1 (10.0.0.2) and wlan0 (192.168.0.2).
My default route is for eth1.
Let's say ...
16
votes
4answers
6k views
How to speed up X over SSH on a slow network connection?
Are there any specific recommendations on speeding up X applications over ssh on a slow network connection? In this specific case, I am accessing a server located in west coast from a laptop in east ...
7
votes
5answers
5k views
How can I limit the bandwidth used by a process?
I have a CentOS 5.7 server that will be backing up its files nightly. I am concerned that visitors to the various sites that the server hosts will experience degraded performance while the backup is ...
3
votes
4answers
2k views
All commands that should be used to connect to wifi in command line
I would like to switch from gnome to awesome and I would like to connect my wifi network in command line (instead of using gnome tools).
So, I searched on the internet and found approximatively the ...
10
votes
3answers
3k views
How to find what other machines are connected to the local network
How can I see a list of all machines that are available on the LAN I'm am part of.
7
votes
3answers
4k views
Only allow certain outbound traffic on certain interfaces
I have rather an odd issue. I have a server with two network interfaces eth0 and eth1. Each are connected to a different network. Each network has a internet gateway. The server has various outbound ...
7
votes
1answer
851 views
Dual network connection
I have a usb cellular modem and a Home LAN connection on my Ubuntu 10.10 box.
Both work independently.
I want to know how to have both connected at the same time, and be able to specify which ...
3
votes
1answer
2k views
How to diagnose a reliably unreliable connection?
Where I'm living now, the internet connection (wired) shows the following weird symptoms. They seem to be independent of whether I use host names or IP addresses.
Pinging works
Skype works
Wget ...
2
votes
3answers
2k views
Send duplicate packets over two Internet connections
I need to duplicate an RTP stream over two different (non-reliable) Internet connections.
On the receiver side, I will probably run a custom program that will use a buffer and rebuild the stream ...
5
votes
2answers
295 views
Share keyboard over network as separate device?
I am trying to achieve something similar to this:
http://superuser.com/questions/67659/linux-share-keyboard-over-network
The difference is that I need the remote keyboard to be usable separate from ...
4
votes
1answer
2k views
What is the loopback interface
What is the loopback interface and how does it differ from the eth0 interface?
And why do I need to use it when mounting an ISO or running a service on localhost?
3
votes
3answers
720 views
How to get list of computers similar to what is shown under “Network” in Windows
In Windows 7 when I click on Network I get a list of computers with the same workgroup of mine. But in Fedora when I click on Network I just get a single item Windows Network and I can't see the ...
3
votes
1answer
177 views
Set up network to share a printer connected to one particular machine on the network
How do I set up my Ubuntu machine to allow other computers to print to it?
The set up is:
All computers are connected to the network
1 dual Ubuntu/Windows 7 netbook
1 multibooting ...
1
vote
2answers
2k views
How to connect two computers via internet with ssh?
I want to connect another computer via internet that doesn't have a public IP.
Is there any away to do this?
3
votes
1answer
670 views
Bridge not working
We want to create bridge (mybridge) on our board over eth0 and eth1 interface. The board runs Linux 2.6.34.9.
Following are the commands:
brctl addbr mybridge
ifconfig eth1 0.0.0.0
ifconfig eth0 ...
3
votes
3answers
2k views
Find out network traffic per IP
We have one central server which functions as an internet gateway. This server is connected to the internet, and using iptables we forward traffic and share the internet connection among all computers ...
3
votes
5answers
348 views
How can I test whether connection to the given host/port is established in Bash?
Currently I'm using netstat for this:
if netstat -an | grep ESTABLISHED | grep $address:$port > /dev/null; then
# command
fi
Is there a more elegant solution?
3
votes
2answers
5k views
Firmware for wireless card on Ubuntu/Debian?
This is a follow up to my previous question about Debian support for Linksys Wusb600n. I have tried running the Ubunut/Xubuntu LiveCDs and the WiFi does not come up.
The Gnome Network Manager menu ...
3
votes
1answer
615 views
Under Ubuntu, how do I set a static IP for firewire?
I am using Ubuntu 10.10 on my laptop, which connects to our network wirelessly. Since it sits on my desk next to my desktop, I have a private network between the two using a firewire cable, because ...
2
votes
2answers
1k views
Setup WLAN interface on Debian
I am trying to configure wlan on my dockstar. I installed wireless-tools, zd1211-firmware and wpasupplicant.
My /etc/network/interfaces file looks like this:
auto lo eth0
iface lo inet loopback
...
14
votes
2answers
5k views
How does reverse SSH tunneling work?
As I understand this, firewalls (assuming default settings) deny all incoming traffic that has no prior corresponding outgoing traffic.
Based on Reversing an ssh connection and SSH Tunneling Made ...
12
votes
3answers
767 views
Can I limit a user (and their apps) to one network interface?
As the title really. I've actually got two scenarios to apply this:
Multiseat Desktop: two network connections both with internet gateways and two accounts doing bandwidth-intensive tasks on each. I ...
11
votes
5answers
5k views
Sending audio through network
This is a rather crazy idea.
I am planing to set up a configuration that would send audio being played on my laptop to my home server via local network so that the sound is played on the server ...
13
votes
7answers
4k views
Faster way than ping for checking if computer online?
I'm writing a wake on lan script for a set of our lab computers. We have sqlite db with a list of the computer hostnames, IPs, and MACs and currently I ping each of them with '-c1' so it doesn't run ...
8
votes
2answers
21k views
Orphaned connections in CLOSE_WAIT state
I've got a SLES machine that accumulates TCP connections in a CLOSE_WAIT state for what appears to be forever. These descriptors eventually suck up all available memory. At the moment, I've got 3037 ...
12
votes
1answer
3k views
Why are the first 1024 ports restricted to the root user only?
This is more idle curiosity than anything else. A friend of mine asked me 'which port range is it that only root can use under Linux?' I told him 0-1024 were restricted. Then he asked my why it was so ...
7
votes
1answer
758 views
Suggestions needed for udev, udisks, autofs, notification setup for a complete automounting solution on Linux
Continuing on Automounting plugged devices in linux, which left things a bit basic. Running Gentoo, I'm automounting a combination of local and network devices on my laptop with autofs-5.0.4-r5. Doing ...
4
votes
2answers
644 views
How to know if a network interface is tap, tun, bridge or physical?
As far as i know, there are 4 main types of network interfaces in linux: tun, tap, bridge and physical.
When i'm doing sys admin on machines running KVM, i usually come accross tap, bridge and ...
3
votes
1answer
2k views
Start network service at boot time on CentOS
I've recently reinstalled CentOS onto a computer of mine. I have OpenSSH Server on it now, as did I before I reinstalled the operating system.
Here's the difference: Before, SSH started without even ...
3
votes
2answers
5k views
Bring down and delete bridge interface that's up
How do I remove a bridge that has an IP address that was brought up manually and isn't in /etc/network/interfaces?
$ ifconfig br100
br100 Link ...
1
vote
1answer
2k views
CentOS doesnt know what the internet is
So I have done my share of investigating this problem...
I just recently created an CentOS 6 VM on my LinuxMint box using VirtualBox. I left all the recommended values the same upon creation (8GB ...
12
votes
4answers
565 views
TCP dies on a Linux laptop
Once in several days I have the following problem. My laptop (Debian testing)
suddenly becomes unable to work with TCP connections to the internet.
The following things continue working fine:
UDP ...
7
votes
1answer
4k views
Why are incoming packets on a TAP interface seen with tcpdump but not with iptables?
A program injects packets on a Linux TAP interface (these packets are coming from a virtual machine). Specifically, these are DHCP requests (so they're UDP). I can see the packets with tcpdump but not ...
7
votes
2answers
5k views
Does mount always require root privileges?
I was under the impression that any sort of call to mount requires root privileges.
But recently I was told "You should instead create appropriate entries in /etc/fstab so that the filesystems can be ...
6
votes
2answers
801 views
linux multiple internet connections load balancing with fail handling
I have two ISP connections and need automatic load balancing between them. I also need to handle failed connections (not use one that does not work).
First link is a PPTP connection (ppp0), second is ...
5
votes
1answer
303 views
What is in the output of “getent ahosts”?
What are the fields printed by getent ahosts DOMAIN?
The output for getent hosts is a simple combination of IP and hostname. The getent ahosts has an additional third field that is, in all my test, ...
5
votes
2answers
300 views
Configuring a vncserver so it's only accessible from my ssh tunnel
Since I use vnc through an ssh tunnel, is there any way I can block the open vnc port that the remote machine is listening on without it affecting my ability to use the ssh tunnel? Both machines are ...
5
votes
3answers
389 views
Suspending my laptop breaks ethernet over firewire, are there commands which can fix it?
As mentioned in this question I am using a firewire cable to provide a private network between my laptop and my desktop, because it makes using the screen sharing program synergy much nicer than using ...
4
votes
2answers
132 views
Discover MTU between me and destination IP
In a case I can use only UDP and ICMP protocols, how can I discover, in bytes, the path MTU for packet transfer from my computer to a destination IP?
4
votes
2answers
1k views
Can't ping broadcast
We're running four computers connected to a hub (yes a hub not a switch) on Fedora 13. They were installed using images from a colleague that has recently left us to go back to school, they may have ...
4
votes
4answers
649 views
Connecting to a network via another pc
What's a simplistic recipe to connect my PC to my WLAN through my laptop?
I have one wireless network, one desktop that (for practical reasons) has no connection to the WLAN, and one laptop with ...
3
votes
2answers
272 views
Connecting to wireless router
According to this manual I tried:
$ iwconfig
lo no wireless extensions.
eth1 IEEE 802.11bg ESSID:"g\xC6isQ\xFFJ\xEC)\xCD\xBA\xAB\xF2\xFB\xE3F|\xC2T\xF8\x1B\xE8\xE7\x8DvZ.c3\x9F\xC9\x9A" ...
3
votes
1answer
1k views
Debian 6.0 system with 2.6.39 kernel dropping packets, sandy bridge hardware
I recently migrated an existing Debian system to new hardware, a core i3 chip running on an intel sandy bridge motherboard. I’m experiencing a very strange problem; when I ping my router, about 50% of ...
3
votes
3answers
2k views
How should I determine the current network utilization?
I want to display the current network utilization (bandwidth usage) of one interface of a Debian box on a website. It is not supposed to be very elaborate or precise, just a simple number such as "52 ...
3
votes
2answers
4k views
/etc/hosts for Debian
I was trying to get a perl script that contacts a PostgreSQL database to work on a server. This script was mysteriously failing. I then realised that localhost was not in the /etc/hosts file.
The ...
2
votes
2answers
2k views
No network connection in CentOS 6.3 Minimal under VMWare Player
I'm trying to replicate in VMWare Player the exact same conditions I have under my Dedicated Server for testing purposes.
Now, the thing is that that when I try to install something, or ping ...
0
votes
2answers
1k views
What could cause network latency on a fresh Ubuntu Server 10.10 install?
I have recently purchased a machine to run an online game server. I put the machine together and have installed a fresh copy of Ubuntu Server 10.10. I have noticed that the game server produces a ...
13
votes
5answers
8k views
Linux: allowing an user to listen to a port below 1024
I need to allow an user (different from root) to run a server listening on port 80.
Is there any way to do this?
