Managing and using network connectivity on a unix system

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5
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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 ...
7
votes
3answers
3k views

How to know if a process is attached to a tap interface?

I sometimes come upon machine with tap interfaces (eg, when KVM is running). How can I know which process is attached to the TAP interface?
2
votes
2answers
1k views

How does iperf calculate throughput and jitter?

I've read that iperf basically tries to send as much information down a connection as quickly as possible reporting on the throughput achieved. This tool is especially useful in determining the volume ...
3
votes
1answer
2k views

debian wireless networking through terminal

I'm starting to use the wmii windows manager and I want certain pieces of information to display on a status bar. If I were to want to display the ESSID for the network, I would have to find it ...
3
votes
2answers
402 views

Network issue in vsat

In my server-client architecture, I multicast 100 MB files to many clients from server via satellite link. Network traversal is through 5 hops. I have the 10Mbps ( i.e. 1250 Kilo Byte per second ) ...
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0answers
1k views

Printing failure at a network printer in linux

I added a network printer to my network by the RedHat Enterprise workstation 6 linux GUI. It seemed that the printer setting did find the network printer. However, whenever I tried to print, the job ...
4
votes
1answer
533 views

Control source address for whois queries

is it possible to execute the command "whois" and choose the outgoing ip for the query? I have mounted several IP's on my network interface "/etc/network/interfaces" for ssl porpuses, but would be ...
5
votes
2answers
4k views

Connection ec2 instance operation timeout error using ssh

After creating a new instance, I am trying to access my instance like below: ssh -i private_key.pem root@my_instance_public_domain but the operation is timing out. I have updated the private key ...
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3answers
1k views

How can I secure an OpenBSD-based Apache webserver?

I have an OpenBSD server that has a running webserver (the built-in apache web srv). How can I harden this setup? I want to only server static html files, no php, no sql.
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1answer
4k views

IPtables string match

I'm trying to write iptables string match rule To block http://domain.com:8888 and https://domain.com:8888 when it matches the supplied string in the rule. And another rule to redirect the ports also ...
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0answers
349 views

openBSD static ip can't connect

I have set /etc/hostname.msk0 to inet 192.168.1.102 255.255.255.0 NONE and /etc/mygate to 192.168.1.1 but still can't ping the router (192.168.1.1) do I need to configure dns to ping ? ...
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1answer
467 views

Bring up alias interface on boot, when the main interface is down

In my CentOS 6.2 server, I have the following configuration for networking: The NetworkManager package wasn't installed on eth0 I have a DHCP configuration on eth0:1 alias interface I have a static ...
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vote
1answer
639 views

Is Traffic Control (tc) broken in Fedora 17?

After upgrading from Fedora 16 to Fedora 17, Traffic Control no longer seems to work. Running # tc qdisc show will output: qdisc pfifo_fast 0: dev eth0 root refcnt 2 bands 3 priopmap 1 2 2 2 1 2 0 ...
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vote
1answer
164 views

Linux tools to choose suitable Cisco ASA 5500

I have a linux webhosting server which attracts DDOS attacks. I want to use Cisco ASA 5500 Series Adaptive Security Appliances to protect the linux server from them. I know there are many factors ...
2
votes
0answers
260 views

Setup DSL Network Connection in KDE

I have recently migrated to KDE from unity (ubuntu 12.04). I have a PPPoE network where I live. Under unity, gnome, xfce I am able to set up a DSL connection and everything works fine. I tested a live ...
2
votes
1answer
11k views

Error, some other host already uses address IPADDRESS

I have the following scenario on my Centos 6.2 server: eth0 : has IP 192.168.50.10 eth0:5 : has IP 10.0.0.1 When I boot the system, everything is up and working. When I run: ifdown eth0:5 and after ...
3
votes
1answer
678 views

Determine whether XBOX 360 is on

I want to determine in close to real-time (up to 5s lag would be OK) when my XBOX 360 is switched on or off over the network. The XBOX gets a static IP address which I know. However the XBOX seems to ...
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vote
2answers
340 views

Interface and alias up at the same time

I have on my eth0 NIC card the following IP alias (I'm running CentOS 6.2): eth0 - IP: 192.168.50.1 eth0:5 - IP: 10.0.0.1 Now, when I boot the server, both interfaces come up and respond, but if I ...
2
votes
1answer
849 views

Enabling bwn in FreeBSD

I am trying to load the bwn driver as a module as mentioned in the man page. However, when I attempted to edit /boot/defaults/loader.conf I could not write the changes to the file, this was attempted ...
3
votes
1answer
475 views

How do I transfer files to a SunOS server via sftp with FileZilla?

According to the admin of the webserver, I should be able to use Filezilla to transfer files to the server but I am getting an error. I set up Filezilla for transferring files sftp - using these ...
7
votes
1answer
912 views

AP randomly gets unreachable for the clients while hostapd is running

I got an old PC running as router which has 3 NIC and 1 wifi PCI card TP-Link L-WN751ND. This box runs Debian Wheezy, hostapd, dhcpd etc. The problem is that AP randomly gets unreachable for the ...
2
votes
1answer
780 views

Changing hostname without errors

I tried to change my hostname according to this guide for Debian based system: I edited /etc/hostname I ran /etc/init.d/hostname start Though there are errors. Always when I write a sudo command ...
17
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3answers
790 views

Limiting a specific shell's internet bandwidth usage

I want update my linux in one shell but by default wget or axel in updater use all the bandwidth. How can I limit the speed in this shell? I want other shells to have a fair share, and to limit ...
36
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4answers
17k views

Throttle the download speed of wget or curl while downloading

Is it possible to throttle (limit) the download speed of wget or curl ? Is it possible to change the throttle value while it is downloading ?
2
votes
2answers
3k views

Cannot connect to fedora on port 80

I can't access to my local sites on a fedora machine from ubuntu. In firefox I get this error: The connection has timed out In fedora iptables I added this line: -A INPUT -m state --state NEW ...
2
votes
1answer
107 views

Is there a way to redirect requests from foo.com to a VM on that server?

I saw a tutorial about redirecting client requests to a specific port to a VM inside the server using IPTables. Is there a way to redirect client requests for foo.com to a VM using only IPTables? or ...
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vote
1answer
4k views

VMware Player on Linux, bridge networking

I am having trouble with VMware Player 4.0.3 for Linux. I am trying to run a Linux virtual machine guest (from the Linux host), but am unable to successfully get an IP address on the guest with bridge ...
4
votes
1answer
5k views

dhcp: Host name lookup failure

I changed configuration of /etc/sysconfig/network-scripts/ifcfg-eth1 and used ifdown and ifup to reset it. Then used ifconfig eth1 dhcp start it does not work and say:dhcp: Host name lookup failure. ...
3
votes
1answer
727 views

CentOS network connection breaks every 5 min

I installed CentOS 6.2 about a month ago and it worked fine. Two days ago I saw that the internet connection is broken, so I reconfigured it. I was able to use it but after a few minutes it broke ...
6
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1answer
4k views

NAT (Internet connection sharing) switching between multiple public interfaces

My Ubuntu 12.04 (precise) laptop has three network interfaces: eth0: wired interface sometimes connected to the Internet wlan0: wireless interface sometimes connected to the Internet vboxnet0: wired ...
5
votes
1answer
598 views

How can I setup a wifi access point to only allow users if they accept an EULA?

I need to setup an access point to only allow users through if they first accept an EULA. To make things slightly simpler, I'm looking into doing this with a unix machine that shares the connection ...
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vote
1answer
1k views

How to share a tethered iPhone internet connection with VirtualBox guest?

I mostly connect to my Linux distros to the internet via a USB iPhone tethered connection (MyWi app). I have just installed an Windows XP guest OS via Virtualbox on Ubuntu 12.04. How do I connect ...
3
votes
1answer
670 views

Verbose DNS query to see DNS query order?

I typically determine the IP of a host by doing: $ host -t A example.com. Is there a more verbose version of this that tells me whats happening in the background, specifically the order of what is ...
1
vote
1answer
577 views

Using google DNS in netcfg

how can I set up my netcfg profiles to use the google DNS servers? I've tried IP = 'dhcp' DNS = '8.8.8.8' but that didn't cut it.
2
votes
2answers
2k views

TOR Transparent Proxy - How does to the TCP redirecting work

I used an iptables ruleset based on the sample ruleset from https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy, Section Linux, Local Redirection Through Tor, to set up Tor as a ...
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vote
2answers
2k views

Configuring a VPN in my CentOS server

My server runs CentOS 6.2. It has two network cards (eth0 and eth1). In my server I have installed CoovaChilli access controller software, that manages the LAN under it. This management is done ...
2
votes
1answer
391 views

Constantly pinging a server

I am not sure if this is exactly the right place for this question, but there is no networking stack exchange. I want to ping a server a bunch of times (eg.10,000+) to gather information on the ...
2
votes
1answer
5k views

DNS Issues on RHEL 6

I'm experiencing some DNS issues on a new RHEL 6 virtual machine. Ping is working fine to an IP, but the machine is unable to resolve any names. I've tried adding Google's DNS servers (8.8.8.8 and ...
4
votes
1answer
6k views

“Destination Host Unreachable” when pinging wireless router

I'm a little new to all the intricacies of Linux workings, so please bear with me if this is a dumb question. I'm using Linux Mint 12 and I have an Asus PCE-N15 wireless card, which is running the ...
3
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2answers
5k views

Where does Debian store network connectivity history?

I would like to know if Debian has anywhere where it stores a history of network connectivity- IP addresses/server, DNS etc?
6
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1answer
354 views

Auto-switch to wifi

Need to connect to specific wifi point as soon as it is in range. If it is out of range, then system must stay connected LAN. In case, any wifi-point is in range, there must be auto-switch.
1
vote
1answer
2k views

Interpreting output from iostat

I'm facing really slow speed serving just static files from 300 to 900 MB on a 1 GBps dedicated line. This is the output from iostat but I don't know if this is ok or not. Linux ...
0
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1answer
57 views

Do IPTABLE rules apply to other devices on a network?

I have an embedded device that listens to a specific port to be programmed by vendor specific software. If I have a network that consists of a small linux computer and this industrial device would ...
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2answers
1k views

SSH into Ubuntu VM remotely

I don't have much Linux or networking experience, but I'm trying to SSH into an Ubuntu virtual machine from outside of my home network. The Ubuntu virtual machine (running inside VirtualBox) is ...
2
votes
3answers
709 views

VirtualBox networking host-only: Linux host XP Guest

I'm having trouble connecting XP ( Guest system on VBOX ) to Debian Testing (host). The version VirtualBox 4.1.12 Relevant parts of the output of commands. ifconfig on debian: eth0 inet ...
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0answers
482 views

Add blinking network-monitor icon to GNOME / XFCE

I'd like to see if I have incoming or outgoing network traffic via a little blinking network-monitor icon in my system tray, similar to the network system tray icon in Windows XP and Android. I would ...
4
votes
1answer
4k views

DHCP server: offer different subnet addresses for different interfaces

I'm running Ubuntu 10.04 on my home router which has multiple network interfaces. I have dhcpd configured to provide addresses from 192.168.1.0/24 subnet on certain interface. However, I'd like to ...
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1answer
984 views

Linux Mint 12 on HP Pavillion DV7 - Wireless is not working

I just installed Linux Mint 12 using mint4win just to test it out. I have a problem with my wireless connection. When I start Mint, it sees the network I wish to join, I select it, enter the correct ...
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1answer
1k views

How can I force a tap/tun interface into the running state?

I am trying to capture packets on a tun interface with libpcap. I am creating the interface with: openvpn --mktun --dev tun0 When the adapter is setup it appears as so when I run ifconfig: tun0 ...
3
votes
1answer
1k views

Linux workstations intermittently lose internet connections

About three months ago, a strange phenomenon started happening in our network. Firstly, let me describe the network layout (only the details which I think I'll be allowed to divulge): We have a ...