Managing and using network connectivity on a unix system

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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
votes
1answer
275 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 ...
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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 ...
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5answers
4k 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 ...
2
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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 ...
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6answers
43k 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
140 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
530 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 ...
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votes
2answers
15k 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
996 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 ...
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1answer
375 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
votes
1answer
751 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
votes
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
votes
3answers
6k 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) ...
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3answers
417 views

Questions about nmap

I have several questions about nmap. First, nmap can detect servers via: link-layer network-layer transport-layer What are the differences (not in the layer, but in the way that nmap does it) and ...
3
votes
1answer
676 views

Filter out HTTP GET request within wireshark?

I'm trying to filter out HTTP GET with wireshark, but the string provided on the official page isn't working at all: port 80 and tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420 Wireshark on ...
4
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2answers
418 views

How can I use one network port for VPN and the other for everything else?

My Linux machine has two network ports with two IP addresses. I want to use one port for my VPN and accounting, and the other port for other usages. How can I tell Linux not to allow any requests from ...
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1answer
3k views

How to run tcptraceroute utility on UNIX machine?

How can I run the tcptraceroute utility on a UNIX machine? I want to run a TCP traceroute for port 80.
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0answers
348 views

Juniper SRX210, how to make DHCP to Static IP?

I am very new to Juniper device. I have a SRX210 router, and i am testing how to setup Static IP. So i did: set interfaces ge-0/0/0 unit 0 description ISP Link set interfaces ge-0/0/0 unit 0 family ...
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5answers
7k views

What is the need for rsync server in daemon mode

I don't understand the need for an rsync server in daemon mode. What are the benefits from it if I can use rsync with SSH or telnet?
4
votes
2answers
3k 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?
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0answers
193 views

configuration for my wireless connection

I had connection issues so I changed some wireless configuration. I think I solved the problem, but I still have minor issues. First thing I had my Internet connection freeze badly, Then after doing ...
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4answers
4k views

Can't Install/Update packages on newly installed CentOS

I installed CentOS6 and it is the first time. I tried to install/update packages. But I coudn't. Here is the output and it doesn't stop. How can I solve this? [root@localhost suranga]# yum update ...
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3answers
49k views

How can I know if IP Multicast is enabled

I have scripts that run IP multicast tests; however, my scripts are failing on a particular linux machine. I know that I can look at CONFIG_IP_MULTICAST in the kernel configuration file to determine ...
3
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0answers
729 views

tunneling FON traffic via Tor

I would like to tunnel the traffic of my FON router through Tor. For that I added a second network card to a local server and connected the FON router to it. Then I set up a DHCP server and configured ...
1
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1answer
439 views

NetworkManager on Fedora 15 can't find frequently used wireless network

NetworkManager has refused to find the wireless network I always connect to. It sees other wireless networks except the one which I need. In recent past occasions, I've had to delete the wireless ...
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4answers
3k views

How to set domain name in Crunchbang GNU/Linux?

How can I set the domain name in GNU/Linux?, I am using Crunchbang and I need to set the domain name for my LAN network. EDIT: Let me talk more about my problem: I need to configure a LAN network for ...
3
votes
1answer
471 views

Labeling/Aliasing multiple network addresses

If my machine is connected to several networks and configured with multiple addresses (ipv4), is it wise to configure and use labels to identify them ? By labels I mean the iproute2 ip command's ...
2
votes
1answer
3k views

iptrace for linux: how can I trace full packet contents?

I normally use iptrace on our AIX servers to get packet traces but have recently found out that this doesn't work for other 'nix systems - namely Centos. Does anyone know what the analog would be? ...
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2answers
4k views

No, I don't want persistent net rules

I have a bootable Linux memstick that I use on a lot of different PCs (but all of the same model and configuration). Trouble is that udev is renaming the eth interfaces so that what was eth0 on the ...
5
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2answers
2k views

What's the next step in troubleshooting this wireless connection failure?

I just installed Ubuntu 10.04.3 to dual-boot with Windows. I can connect to the Internet using a wired connection, but not through wireless. The first time I booted, the wireless notification bar ...
4
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1answer
6k views

CentOS doesn't know what the internet is

So I've done my share of investigating this problem... I just recently created a CentOS 6 VM on my LinuxMint box using VirtualBox. I left all the recommended values the same upon creation (8GB HDD, ...
4
votes
1answer
157 views

connect() blocked for 3 seconds after a lot of success connect()

I am writing a client-side application which connect() to a server and close it in a for loop. The connect() is done in blocking-mode, and I found that some connect() call will block for about 3 ...
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2answers
376 views

Is it possible assigning an separate LAN IP to service/daemon?

I'm using pfsense for prioritizing traffic around LAN. It works well for specified port, IP, network, but I'm having a problem with torrent (transmission bittorrent) outbound connections. The outbound ...
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2answers
486 views

UDP NAT Punching

I have the following two problems. Please help me to solve them: In symmetric NAT, as I know, the local hidden node (behind the NAT) must initiate connection in order to create a window in the NAT ...
3
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1answer
801 views

How can I update the OUI list used for Netdiscover?

Netdiscover keeps showing a lot of "Unknown vendor" devices, when I generally can find the vendor pretty quickly via Google. Is there any way to manually update whatever OUI list Netdiscover uses?
3
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0answers
685 views

Wireless rtl8187 freezes intermittently

I am using a wireless USB ALFA 036H. Linux Mint (32-bit) recognizes it without any drivers but it stops downloading/uploading and I have to reconnect to get it to work again. I tried to find a ...
2
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2answers
2k views

Checking the type of NAT

I have read that there are many types of NATs available like symmetric NAT, full-cone NAT, etc. If I am behind a NAT, is there any way to find out the type of NAT behind which I am currently working ...
2
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0answers
788 views

Mount Freecom Classic SL Network Drive (NDAS) in Ubuntu 11.10

Both the Network Drive and the Ubuntu machine are connected by Ethernet to a Linksys WRT54GL router (192.168.1.1). To access the Network Drive in Windows, I installed the NDAS software and mounted ...
2
votes
1answer
706 views

Is vnstat reporting accurate?

I'm checking the stats of a busy site that host mirror downloads. I installed vnstat on the machine and after a few days i saw the number 125.25 Mbit/s or using -ru 0 15.29 MiB/s I'm extremely ...
3
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2answers
1k views

Why does my USB wireless network adapter disconnect every few seconds?

I don't have experience with drivers and other things. After installing Linux Mint 11 on my machine (I did a dist-upgrade), everything seemed to be great -- I didn't need to install any drivers. After ...
2
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1answer
754 views

VirtualBox host-only network suddenly stopped working , no interface available inside

I'm unable to setup host-only network in virtualbox suddenly , please see my screenshot , there's no entry in "Name" comboBox
1
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2answers
519 views

Network file sharing with freebsd server

I have a freebsd server at home. I also have other OSes like linux and windows connected to the same network via WLAN (wifi). I want to be able to share stuff (what ever I download ;)) on my FreeBSD ...
2
votes
1answer
1k views

Atheros ar8151 driver for kernel 3.x (fedora 16)

Yesterday, I installed Fedora 16 and found no wireless connection available. Then I found the ar81family driver But it seems like it does not work with kernel 3. I changed the makefile to ignore ...
3
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1answer
210 views

Doing nmap on a network

I used nmap to scan all the ports in the hosts in a network by using the command: $ nmap 172.31.100.0/24 What I found is that it showed the following in the result: Nmap scan report for ...
6
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2answers
666 views

How can I test the current carrier state for an ethernet adapter in Linux?

In Arch Linux, how can I check if a network device (say eth0) has a carrier signal present?
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3answers
5k views

How I can know the IP address of other users logged at the same remote machine?

I can see the names of other users on the remote machine with the who command... I'd also like know the IP address of those users... I was trying with the commands /sbin/ifconfing and netstat but I ...