Managing and using network connectivity on a unix system

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CentOS 5.5 network problem

I have been made to install CentOS-5.5 on my desktop. The network is not working. These following are the outputs of various commands. #ifconfig lo link encap:local loopback inet addr 127.0.0.1 mask ...
2
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2answers
619 views

How to identify the program that uses most bandwidth?

How can I know which application is using the most network bandwidth? I saw some graph from KDE's network monitor, but don't know which process did that.
3
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3answers
408 views

how can I give a normal user write access to a network interface?

I have a program that reads and writes packets to/from network interfaces, and normally I would add myself in the sudoers file and run the program like this: sudo ./bridge But now I need multiple ...
1
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1answer
5k views

Can't use my USB wireless adapter D-link (DWA-131) to work Backtrack5 R1 VMware

I have a USB wireless adapter D-Link DWA-131. I also have backtrack 5R1 on Vmware. I installed the driver on the system, and here are some outputs: root@bt:~# lsusb Bus 002 Device 001: ID 1d6b:0001 ...
2
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2answers
1k views

How can I Forward a subDomain to a specific port?

My apologies if this has been asked before. I haven't found an adequate solution so... yeah. When a specific domain, "example.com" is accessed, I want it to act normally. In other words, it should go ...
2
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0answers
952 views

pfsense long ping to google

I have a pfsense box set up. What happens is I set a rule so I can't hit the admin interface 192.168.3.1 from the box. With the rule enabled --- www.l.google.com ping statistics --- 2 packets ...
11
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2answers
38k 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 ...
3
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1answer
681 views

What happens if you add a vlan-device to an interface that already is a vlan device?

When configuring an application that creates vlans by using vconfig add, I discovered that it was adding a vlan device to something that was already a vlan device. Effectively, what happened was: # ...
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1answer
641 views

routing between two private networks (NICs)

I have two private networks say: 10.0.1.0/8 and 192.168.0.0/24 I have two machines with two NICs per each machine. machine1 NIC1: 192.168.0.10 machine1 NIC2: 10.0.1.10 machine2 NIC1: 192.168.0.11 ...
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2answers
2k views

Is there a tool to display WiFi information in console?

Can I view detected WiFi networks details (like signal strength, encryption etc.) in command line? The more detailed - the better.
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2answers
2k views

ping -c1, wait for all responses from broadcast

I want to send one packet to the broadcast address, but wait for all responses. If I do ping -c 1 192.168.1.255, it sends just one packet, but it quits after getting the first response.
2
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1answer
114 views

Gentoo on VM setting IP Manually

I installed Gentoo on Virtualbox with the minimal image. This is the first time I am running gentoo. I need to do ifconfig eth0 192.168.0.10 route add default gw 192.168.0.1 everytime it boots on ...
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3answers
168 views

Did all of the Requests for Comments directly affect the design of Unix networks?

I want to know more about Linux must be one of my most enduring sentiments. But I often find that I learn the most, or perhaps just feel the most satisfied with what I have learned, when I simply ...
1
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1answer
347 views

Sharing Mobile Internet To Others

Currently I am using a mobile internet connection using an USB cable. How do I share this connection with my peer who only has a wireless card on his macbook? So far what I have tried: Internet ...
1
vote
1answer
836 views

Failed to get access to the Internet after disabling networkmanager on ArchLinux [closed]

How can I get access to the Internet after networkmanager is down? I disabled the networkmanager and uncommented the static IP settings I used to use and reboot, but I'm still unable to get access to ...
15
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1answer
1k views

“ss” command in iproute package; why query slab table for timewait sockets?

Forgive me if this isn't the best forum for this question, but it seems more relevant to the kernel than to the programming itself. I'm writing a script that queries the system for open ports so that ...
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0answers
157 views

Network Interfaces Don't Exist After Loading Modules

I installed SourceMage Linux on my laptop and the ethernet and wireless interfaces don't exist after loading the required modules (tg3 and ath9k). On other distros (Xubuntu, aptosid) the networking ...
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4answers
2k views

Why do we need a firewall if no programs are running on your ports?

When I try to telnet to a port on a server, and if there is no program listening on that port telnet dies with a "Unable to connect ... " error. I understand that. But, why do we need a firewall if ...
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2answers
1k views

Per Socket network Buffer queues utilization

Is there a way to get a per-socket send and receive Queues utilization on Solaris similar to the way that Linux' netstat displays it? Example on Linux: Proto Recv-Q Send-Q Local Address ...
5
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3answers
25k views

how to ping & use specific network card

i have 3 network cards , 1 Lan (wired) , 1 wireless network card & 1 is wireless usb how do i ping from specific network card ? & how do i use specific network card for specific ...
4
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6answers
895 views

Find my computer on a LAN network

Let's say that I have a computer plugged in to a local network using a dhcp connection, so it will get a different IP every time. Is there a way to find this computer (so the IP) from a different ...
5
votes
1answer
804 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, ...
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2answers
216 views

How can I use the same IP from the Internet and intranet?

I have an Ubuntu firewall box (Alma), at the office, with a web server on it. It looks like this: [Internet] <-> [DSL Router] <-> [Alma] | ...
3
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2answers
6k views

How do I resolve samba share to IP address or host name

I have a list of hosts in the network providing shares via SAMBA. How can I determine either IP address or the host name of one particular host, e.g. the one with the name “SASAK02”. The output of ...
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1answer
1k views

How to transfer files over bluetooth?

How can I connect my mobile phone and Lubuntu 11.10 laptop over bluetooth so that I can transfer files between them?
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0answers
270 views

virtual network interface for ShrewSoft VPN Client

I use ShrewSoft VPN Client 2.1.7 under Arch Linux (i686) to connect to the company network using IPSec. It is configured by a .vpn file. How can I make it create a virtual network interface?
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2answers
767 views

Need help with routing

I have set up a Ubuntu server, that I want to use as a router for my local office. The problem is, that I want to make 2 VPN connections, to remote branches, and then I want to route all traffic to ...
9
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2answers
5k views

Merging two internet connections from two network interfaces in order to obtain double speed

I have two network interfaces (one wired & one wireless). I have two internet accounts too (each 256 kBps; one from a modem that I use as wired connection & the other from a wireless network). ...
2
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2answers
236 views

How to prevent user applications from knowing about network failure?

I have a very unreliable connection which disconnects quite frequently and becomes a massive problem when downloading, as the option to resume is not always available. The solution that comes to my ...
2
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1answer
1k views

Ubuntu machine with RNDIS tethered phone can not receive packets from internet

I tried to tether my old Windows Mobile 6 phone with my Ubuntu computer to use the phone's network. However, even though the kernel seems to recognize the phone and it is used as a network device I ...
6
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2answers
5k views

How to build a gateway from my Linux OS

I want to configure my Linux so that it will be used as a network router (gateway). Can anybody give me some hints on this? (links are welcome!)
2
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1answer
7k views

Static route in Centos 6

Here is my route -n output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 ...
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7answers
53k views

What DNS servers am I using?

How can I check which DNS server am I using (in Linux)? I am using network manager and a wired connection to my university's LAN. (I am trying to find out why my domain doesn't get resolved)
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2answers
8k views

changing the names of network interfaces, debian wheezy

I'm trying to set a name for an interface, "ethLan" instead of eth0. Doing so also ensures that the if's name will remain consistent at every reboot and kernel. I did find some articles in the ...
4
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1answer
281 views

Inserting a nat solution into a network while it's not the gateway

I have tried this a few different ways. Currently trying with pf on freebsd 8.2 I am trying to insert a nat solution into an existing network that will redirect traffic from an outside ip address to ...
1
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4answers
22k views

WiFI access in BackTrack 5 R1

I recently started using a live USB version of BackTrack 5 R1 (A kubuntu-based distro), but I can't find any way to enable access to my home WiFi network. I can't find any comprehensive tutorials on ...
2
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5answers
5k views

script to scan ip range and return results in a certain format

This script scans IP's and returns a status of Up or Down. How can I alter it so it doesn't scan everything twice? As it sits it scans everything and returns the "Up" addresses only and then scans all ...
3
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3answers
5k views

Auto connect to a wireless network (Ångström Linux)

I am using Ångström Linux on BeagleBoard-xM. I have installed a RTL8188SU USB Wi-Fi adapter and configured it properly. But it doesn't connect automatically even though I have marked the interface as ...
23
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6answers
45k views

How to limit network bandwidth?

Problem: We are hosting an application on remote server. We need to test it with a limited network bandwidth (for users with bad Internet access). Question: Can I limit my internet bandwidth (in ...
2
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1answer
3k views

Testing if a port was forwarded correctly in Ubuntu

I have a Ubuntu box connected to a wifi router. This wifi router is connected to a d-link adsl modem/router. I am preparing this Ubuntu box to run a server that will use some special ports in UDP and ...
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1answer
145 views

Linux 3.x: what wireless chipsets will support a bridged connection?

I have asked a similar question on the Ubuntu pages but this is likely a generic Linux issue: what variety of wireless cards/drivers will support being placed in a bridged connection? I have been ...
49
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2answers
6k views

How does SSH connection survive a network restart?

From a Linux SSH shell, type /etc/init.d/network restart to restart the network service. I expect my SSH connection to die since the network service goes down. But it doesn't. Very cool. But how does ...
2
votes
1answer
539 views

ICMP destination unreachable

I am working on an Arch Linux machine with an ethernet interface eth1. I have created the interface eth1:0 using ifconfig and given it a dummy hardware address (00:01:02:03:04:05). When I send a UDP ...
6
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2answers
16k views

Check whether network cable is plugged in without bringing interface up

I am trying to identify NICs on ~20 remote servers (2-6 NICs on every server). To begin with, I want to identify those ready for use and free ones. How can I check the state of the physical media? I ...
5
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2answers
1k views

how to set what route would be added when bringing interface up

I have one two interfaces on one machine, one is the Internet connection that get its IP from a DHCP, no problem. The other interface (eth1) is to local machines, and it has the gateway 192.168.3.1 ...
3
votes
1answer
385 views

Configure applications to ask for a user:pass behind a proxy

Here's the deal: I'm trying to set up a SQL server with Debian Linux, I managed to install Debian - but I can't get apt-get to work, since I'm behind a proxy. I already managed to setup Iceweasel to ...
3
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1answer
765 views

How can I network these two computers using eth1394/firewire-net, automagically?

I have two partly-dead laptops. The first will not run X, and the second has some sort of problem with the monitor. I am not interested in repairing either of them, but since they both have firewire ...
2
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5answers
2k views

full access to remote computer without remote static IP

How can I access to remote computer that the remote computer is in a local network? I worked with reverse ssh : http://www.vdomck.org/2005/11/reversing-ssh-connection.html I don't want just SSH but I ...
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3answers
7k views

What's the last number in this ip address?

An IP address like this 223.248.0.0/24 or 223.248.0.0/16 What's the last number mean in the IP address (24 or 16 in the above example)? Is there a simple way to understand how to set the number ...
2
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3answers
7k views

Can ping any hosts but localhost. What's wrong?

I got a freshly installed red hat box on a server. I can ping another machine on the network usnig both ip and server name but I can't ping localhost or 127.0.0.1 or 192.168.4.42 (local ip) ...