Managing and using network connectivity on a unix system

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2answers
388 views

How to find transmission speed?

Two host machine's one as a client and other as a server, i am testing udp load-test in these two machines.Machine Ethernet speed is 100 Mbps but i want to send 30000 packets each of 512 bytes at 1 ...
2
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1answer
804 views

Changing service startup order

I use wpa_supplicant to configure the wireless connection. Now I have a problem in that the network service starts before wpa_supplicant so this happens: Bringing up interface wlan0: Determining IP ...
3
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2answers
609 views

Meaning of log entries from an iptables configuration

My router has Linux as its OS. The system log has a lot of rows about iptable and klogd that I don't understand, could someone explain them to me? The iptables setup: iptables -t nat -A PREROUTING ...
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0answers
227 views

No ports can be found using port scan

Problem: I have a laptop and a server (Home-Server) with fc17. They are both using the desktop environment. I am trying to set up a VNC server on Home-Server so that I can set everything up without ...
2
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2answers
4k views

How to tell who is connected via vnc to my machine?

How do I check how many vnc connections or different users are currently connected to my machine? Only through wireshark? And how do I kill any other users connected through vnc?
2
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2answers
3k views

DNS Master vs Slave and Primary vs Secondary

I'm a little confused about the difference between a "secondary name server" and a "slave name server" and a "primary name server" and a "master name server"   I understand that a slave name server ...
0
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3answers
4k views

How can I reinstall Network Manager after uninstalling it?

I am running a version of RHCE6 on my laptop, and lately I've been trying various stuff about network configuration through command line. Last night, I tried removing the NetworkManager using yum ...
1
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0answers
316 views

How can I renew lease when it kept printing eth0 lease expired x seconds ago?

My guest VM cannot get an IP address from my host. It keeps printing: eth0: lease expired x seconds ago I've tried to start dhclient -r and dhclient and restart eth0 to no avail, see here for ...
3
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2answers
724 views

Set the preference for sending packages through an specific network device

I have SL 6.3 installed on two machines. Machine A is a workstation and has two interface eth0 and wlan0. Using eth0, it is connected to Machine B (public facing server) with static IP address. Both ...
6
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1answer
887 views

What is “link beat”?

I have a Linux 2.6 box that uses ifplugd to bring up the network. While initialising, the logs say, "Initialisation complete. Link beat not detected." and then it goes into releasing the present ...
7
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2answers
3k views

How do I find the process generating a lot of network traffic?

My machine is generating a lot of network traffic, all from the same source port, with many different destinations (found this out by running iftop -P, and from my router's logs). How do I find the ...
0
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0answers
593 views

Changes made to ifcfg-wlan0 doesn't seem to make a difference

I am running RHEL6 on my laptop. The wireless adapter configuration file ifcfg-wlan0 didn't come by default under /etc/sysconfig/network-scripts. So I created it myself. The problem is, whatever ...
2
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1answer
347 views

Configuring Wireless Network

After a long struggle I finally seem to have installed the non-free wireless firmware for my wireless NIC. I'm trying to set up a file server, so I want to configure the network to be static. Would ...
3
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2answers
5k views

Driver for Intel 2200BG wireless network card

I'm trying to make work my wireless network card Intel 2200BG in my laptop Acer Travelmate 4002WLMI. I tried so far: $ sudo lshw -C network *-network:1 description: Wireless interface ...
4
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1answer
3k views

nsswitch.conf versus host.conf

Suppose that /etc/nsswitch.conf file contains hosts: files dns and /etc/host.conf file has order bind,hosts then in which order the system would use /etc/hosts and DNS look-up to resolve a host ...
2
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2answers
10k views

Where could I find the ifcfg-eth0 file?

I am using RHEL6, but I could not find the Ethernet interface configuration file ifcfg-eth0 under /etc/sysconfig/network-scripts. Issuing ifconfig -a shows that eth0 does exist. Could it be that the ...
3
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1answer
6k views

What is the difference between virbr# and vnet#?

I am running KVM on RHEL6, and I have created several virtual machines in it. Issuing ifconfig command to the host system command line shows a list of virbr0, virbr1... and vnet0, vnet2... Are they ...
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1answer
2k views

Network Interface Names output from ifconfig

So this has been driving me nuts for a good couple of hours, so I thought I'd ask about it here (let me know if there's a better forum for this question). I have a CentOS Virtual Machine on ESXi. I ...
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0answers
136 views

Unable to access internet if wireless enabled

The following is my route output. eth0 is my wired network and eth1 is my wireless network. Only wired one has access to internet. If I enable wireless, I am not able to access internet, it tries to ...
2
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0answers
621 views

Missing Firmware for Wired NIC on Debian

I'm trying to install debian 64bit from a debian live image using YUMI on my usb drive. I'm installing it on an Inspiron 6400, and there is missing firmware. I can't connect to the internet ...
2
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2answers
3k views

Why doesn't eth0 get an ip address when set up in a bridge?

I'm trying to understand how dhcp for IPv4 is used with bridging. eth0 is configured to be in br0. This is working just fine but only br0 gets a dhcp lease, while eth0 doesn't. Both are configured ...
1
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1answer
466 views

How to get the cloned guest connected to the Internet?

I made a clone of a VM(running a version of Centos 6) on KVM, but the clone wouldn't connect to the Internet. Issuing ifconfig shows no interfaces but the lo. Interestingly, the original system can ...
1
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1answer
541 views

How can I resolve local IPs to hostnames? [duplicate]

Possible Duplicate: How to make a machine accessible from the LAN using its hostname I have is a simple home network with a few machines connecting through DHCP. If everyone and their ...
1
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1answer
2k views

ifconfig + FAILED from ifconfig on solaris machines

please advice - what the meaning of FAILED word from ifconfig command Dose its mean that network from NIC isn't stable until this moment ? Not clearly if ifconfig read network status each some mili ...
0
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1answer
863 views

Why does sshd accept local network inbound connections and refuse external inbound connection?

When I try to connect to my server from the internet, I always get: debug2: ssh_connect: needpriv 0 debug1: connect to address XX.XX.XX.69 port 22: Connection refused ssh: connect to host XX.XX.XX.69 ...
7
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1answer
368 views

Installing USR 5422 on Ubuntu 12.04

I am a newbie to Linux. I was trying to set up the USR5422 USB adapter. It worked fine for the first time, but since then it freezes the computer most of the time. What commands can I fire to see ...
1
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1answer
1k views

Alternative to ethtool on MontaVista embedded Linux

I am running MontaVista Linux Professional Edition 3.1 on an embedded system. My version of this distribution doesn't seem to have ethtool available, and using mii-tool gives the following error: ...
2
votes
1answer
732 views

How to config iptables for pppoe?

When I create the only rule disabling all input, iptables -P INPUT DROP I can not connect anything. So it looks like I should allow some incoming activity to get PPPoE working correctly. What rules ...
0
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2answers
110 views

How do I set up a small personal network with Linux? [closed]

I want to take the time to get into building a useful network for use between my personal machines using Linux. I have spent a lot of time scouring the web for resources on how to do this but I am ...
2
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2answers
724 views

Bandwith monitoring in Linux

I just need to get how much bandwidth is used in 3 or 4 days. Do you have any application in the terminal to do it? I'd prefer if it didn't use SNMP. I found iptraf, wireshark, cacti, but they were ...
1
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3answers
330 views

How can I view and play shared audio files through a network?

I've come up with a quick pet project (which might, maybe, even end up being useful at my home someday); the idea is to allow users of a Linux device (I'll call it A, and it'll probably be a small ...
1
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1answer
3k views

Redirect Output with Iptables

Is possible on Debian to change the port of packets that are going to a specific port, using iptables? Example: I want packets going in the outbound direction to a.b.c.d for port 1723 to be ...
3
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1answer
573 views

Ubuntu networking: can't connect to LAN

I have a server with Zentyal 3.03 (Ubuntu 12.04) LTS. It has 3 network devices: eth0 - dhcp fast internet (I pay for it) eth1 - static slow internet (it's free for the school) eth2 - LAN I can ...
1
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1answer
524 views

No network in slackware

I have just installed Slackware. I am not new to Linux but new to Slackware. I wonder how to install network in it. After the Slackware installation, audio and network were not working. This is ...
0
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1answer
78 views

What to make of system scans reported by psad

My system logs show that psad detects scans like this every minute. psad: scan detected: 192.168.1.10 -> 192.168.1.1 udp: [53] udp pkts: 2 DL: 2 If the first address is mine, and the second ...
15
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3answers
34k views

Can't ifdown eth0 (main interface)

I can't ifdown an interface on a Debian 6.0.5 box; user@box:/etc/network$ sudo ifdown eth0 && sudo ifup eth0 ifdown: interface eth0 not configured SIOCADDRT: File exists Failed to bring up ...
7
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2answers
1k views

What are the ramifications of setting the hostname?

I have several Amazon EC2 servers and I'm using Chef to manage the configuration. I'd like to set the hostname so that the default bash prompt is more helpful. Right now after launching a new server ...
3
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2answers
4k views

How do you configure the MTU for all network adapters via a script?

NOTE: This is for RHEL/centOS. Currently my way of configuring the MTU is via GUI using system-config-network and setting the MTU to 4096. I would like a non-interactive script to do this instead. ...
1
vote
1answer
196 views

Usb-ethernet device

I have CP210x Composite Device. This device is USB-to-RS232 converter. When I plug it into Ubuntu-11.10, module named cp210x get inserted but I don't know why it did not create "usb0" network device ( ...
11
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3answers
16k views

How to configure external IP addresses for LXC guests?

I'm exploring the LXC features in Ubuntu 12.04 and I really want to set up a network like this: client1: 192.168.56.101/24 lxc-host: 192.168.56.102/24 guest1 192.168.56.201/24 guest2 ...
10
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2answers
368 views

Linux program to look into what you're downloading

Is there a linux program that allows you to look into your current download traffic? Something that can list all the addresses I am currently connected to and downloading from.
16
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3answers
16k views

Linux network troubleshooting and debugging

From time to time Linux and Unix users faced with various network problems. Many of these problems are presented here and at some others troubleshooting forums, but the are very concrete and contains ...
5
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2answers
5k views

Monitor mode wifi only seeing broadcast packets

I have pretty much exhausted every link I have found on google regarding this topic, and I'd like some of the most experienced eyes on the problem, because something obscure must be going on. Systems ...
1
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1answer
666 views

Reducing ubuntu boot time using dmesg

The boot time is 141 seconds. Here's the most interesting parts of dmesg command: [ 2.870498] usb 1-1.2: new high-speed USB device number 5 using ehci_hcd [ 80.669210] ADDRCONF(NETDEV_UP): eth0: ...
0
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3answers
3k views

How to setup wine for networking in linux

How to setup wine for networking? Unless i have linux access to my windows network, i can't do wine discover the windows network. How to do it?, also wine hasnt cmd line utility so i can't use ...
2
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1answer
3k views

How to Connect to Wireless Automatically? (Non-graphical)

I'm trying to set up my Arch Linux so that, through non-graphical means, I can connect to a wireless network through profiles on my system. I have tried net-auto-wireless, and it does everything I ...
2
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1answer
1k views

RHEL how to sync network settings between GUI and configuration files in /etc/sysconfig/network-scripts/?

In RHEL, we can change network settings either using GUI or editing the configuration files in /etc/sysconfig/network-scripts/. I would like to know how the network settings (e.g. IP address, ...
14
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4answers
1k 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 ...
2
votes
2answers
126 views

Cannot Restore LAN Connection

I have two servers, 198.162.0.4 and 198.162.0.10, that were connected across a LAN. They are the components of a DMZ where 198.162.0.4 is the wen server and 198.162.0.10 the application server. ...
2
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2answers
928 views

Quickly check whether many network hosts are up-and-running

Objective: check if a host is up-and-running on the network, with a method that can be efficiently parallelized over many hosts. Emphasis on a QUICK turnaround of the check. Reason to emphasise ...