Managing and using network connectivity on a unix system

learn more… | top users | synonyms (1)

2
votes
3answers
3k views

Programmatically extract private IP address(es)

I'm looking for an easy way to programmatically extract the private IPv4 address(es) of a computer. Something similar to this question, but restricted to private IPs. As an example, I can extract ...
3
votes
1answer
531 views

VLAN setup on CentOS

I have two networks I want to separate from each other (no inter-routing). I'm using a Linux host as a router and I have a Juniper switch as the switch (obviously). My LAN interface on the Linux ...
3
votes
2answers
841 views

Converting Webserver Logged IP Addresses to DNS

I'm trying to use a bash script to process a webserver log file and replace any IP's it finds with their corresponding DNS hostnames. An example entry of a single line from the log file is: ...
5
votes
2answers
3k views

How to assign an additional IP/hostname to a chrooted environment?

While I can simply have e.g. sshd in a chroot environment ("chrootenv") listen to a different port than its parent ("parentenv"), it would be more convenient to have that environment have an ...
6
votes
1answer
1k views

getaddrinfo() from shell? [duplicate]

When you call ping name.domain, it goes through both /etc/hosts and the DNS resolver to obtain an IP. It could be an IP hard-coded in /etc/hosts, or it could be one from the DNS server. It does so by ...
5
votes
2answers
3k views

My Ping command does not seem to ever finish. Does that mean it is suceeeding?

I am pinging a remote IP. I know very little about the Ping command. When I ping the IP, it keeps going and going... I am not using the -t option. Me$ ping 137.30.124.104 PING 137.30.124.104 ...
0
votes
1answer
2k views

Mint 15 on Lenovo G700: wired internet not working (Atheros QCA8172)

Mint 15 doesn't see internet after installing it in dualboot with windows 8 (in Windows internet works well). My network card is Qualcomm Atheros QCA8172 Fast Ethernet (rev 10). What I did: Install ...
3
votes
2answers
4k views

run a script at shutdown in Debain

I am using Debain wheezy. My problem is , I am using a limited 2.5 GB net connection. My idea is simply running a script as #!/bin/bash date >> ~/mydatausage.txt ifconfig -a >> ...
2
votes
1answer
847 views

network traffic monitor in Debian?

I am using Debian wheezy. I am using a limited connection for Internet with 2.5 GB data limit. So I shouldn't use Internet beyond that limit. are there any available data monitors which can do me such ...
1
vote
1answer
438 views

network device name is changed by itself

I use a Ubuntu-arm, uname -a Linux arm 3.7.8-x8 #1 SMP Sat Feb 16 04:15:13 UTC 2013 armv7l armv7l armv7l GNU/Linux I have two USB WiFi interfaces that are named wlan0 and wlan1 on ...
1
vote
2answers
8k views

Can't get Intel I210 ethernet working on Debian wheezy

I have a server with an Asus P9D-I mainboard. It has two onboard Intel NICs: # lspci -nn | grep Eth 01:00.0 Ethernet controller [0200]: Intel Corporation I210 Gigabit Network Connection [8086:1533] ...
1
vote
1answer
462 views

Bandwidth throttling per user group

I am wondering if it is possible to create a bandwidth shaping/throttling script that shapes traffic based on user group. That is, if user1, user2, are in user group group1, they will have 1mb/s ...
4
votes
4answers
22k views

does the gateway have to be on the subnet?

I was looking at bringing up an interface like this in /etc/network/interfaces (this is on debian), with the gateway outside the subnet: iface eth0 inet static address 10.100.10.99 netmask ...
1
vote
0answers
348 views

Local Server not accessible on Linux

My Internet company set up a local server, where different files are hosted. I can download files at much higher speed from there. But for some reason, the server is not accessible from Ubuntu 13.10 I ...
0
votes
0answers
370 views

What is causing my UMTS modem to hang up?

I am trying to established PPP communication to my mobile ISP with wvdial, but I always get modem hang up message. In my syslog I can see some activity: Oct 29 07:48:47 linuxbox kernel: ...
1
vote
1answer
1k views

What makes a good network planner software on Linux?

I need to design a VoIP network topology for a customer and I need a software that can do as that famous Windows one, don't remember the name.
1
vote
1answer
395 views

Directing hostname to another computer within lan using hosts file

There seem to be more questions like this, excuse me if this is similar. I want to redirect to an IP address om my server computer. This is what I put in my hosts file on the client computer (IMac): ...
0
votes
2answers
1k views

Realtek drivers prevent detection of eth1 interface?

Here's the situation: I had a working network setup on my Debian box, with two Ethernet interfaces being reported by ifconfig - eth0, and eth1. eth0 is an onboard Realtek NIC, and eth1 is a D-Link ...
0
votes
1answer
304 views

configure iptables to accept incoming requests

Let me clarify: I have an iMac wich is wireless connected to the router from the ISP. The Centos computer is connected to the iMac with a cable and internet sharing is turned on. Installed Nginx on ...
1
vote
2answers
2k views

How to use netstat command

My question is what does it mean to LISTEN or ACCEPT on a port as it relates to my example? Example: I have a tomcat server, and It will use port 8080. I want to make sure that port is available for ...
15
votes
2answers
13k views

How to identify a process which has no pid?

I have a process which listen to 2 ports : 45136/tcp and 37208/udp (actually I assume it is the same process). But netstat doesn't return any pid : netstat -antlp | grep 45136 tcp 0 0 ...
5
votes
1answer
5k views

log network activity in ubuntu server

I administer an Ubunu Server exposed to the internet and have the need to monitor and keep track of all the network activity in a manner that allows me to analyze it afterwards. I already tried some ...
3
votes
1answer
446 views

Cheapest linux devices? [closed]

I'm getting interested in ultra-cheap linux devices lately. So far I've been playing with some no-name "3G/4G router" devices from amazon (such as this $10 job ...
1
vote
2answers
227 views

Accessing a different computer on the network

At work we have a large network of computer, some linux, some windows. On a windows machine I can go in to my computer and access a network drive simply by typing \ip-address\folder. It'll often ask ...
1
vote
1answer
857 views

How does KVM set its own netfilter rules?

I've been poking around with KVM VM's on Centos 6.4 not having an internet connection on my VM's, I found something curious: Upon booting the machine, iptables has rules in the FORWARD chain to allow ...
3
votes
1answer
554 views

How do I accept all Networks with the same ssid with wicd?

We have a Mesh network here in my town, where every node creates the same client wlan with the SSID "kiel.freifunk.net". In wicd I can connect to those networks, but I have to choose which of them. ...
1
vote
1answer
1k views

Is it possible to add/remove arp-ip-targets without taking the bonding interface up/down

i just changed in /etc/sysconfig/network-scripts/ifcfg-bond0: BONDING_OPTS="mode=active-backup arp_interval=1000 arp_ip_target=10.0.0.1" and now i want to set those arp_interval and arp_ip_target ...
1
vote
1answer
227 views

failure in connecting to my server through ssh

My goal: I want to be able to ssh to my workstation from external client. My workstation(in the following also referred as server) is on a lan. Its ip address on this lan is obviously different from ...
3
votes
2answers
5k views

What does ifup do when “/etc/network/interfaces” has an invalid netmask address?

The interfaces file looks like below: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.0.130 netmask 250.255.255.0 gateway 192.168.0.254 As you can see ...
3
votes
2answers
2k views

How do I fix iptables in ChromeOS?

Using the shell in chrosh in ChromeOS I followed some (apparently terrible) advice to flush my IP tables. using the command sudo iptables -F I am now unable to connect to the internet at all. All ...
13
votes
4answers
3k views

How am I supposed to edit files on a network with Vim?

Currently I'm doing it by SSHing into a server, and executing Vim on the server. This has the benefit of not having to deal with cumbersome syntax of opening files from a remote server over SCP, and, ...
1
vote
2answers
892 views

Restarting network service for a local VM via SSH

During the course of practicing switching my local VM from static IP to DHCP and vice versa via system-config-network, I decided I didn't like having to access the VM's console through virt-manager ...
2
votes
1answer
1k views

Linux CentOS 5.5 not connecting to Network

I have installed Linux CentOS 5.5. During installation, I configured the LAN driver and gave it an IP address. After installation, I checked the network connection but it shows "not connected". I ...
3
votes
1answer
2k views

sshfs will not use ~/.ssh/config (on Linux Mint 15)

Local: Linux Mint 15 - Olivia /proc/version: Linux version 3.8.0-19-generic (buildd@allspice) (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) ) ssh -V: OpenSSH_6.1p1 Debian-4, OpenSSL ...
1
vote
2answers
2k views

Open a port CentOS

I'm new in CentOS and I'm trying to create a little script in Python, something like: $ python -m SimpleHTTPServer If I try to access port 8000 in my web browser, I don't get access, however if I ...
1
vote
3answers
3k views

Split DNS (bind9), match-clients any doesn't work?

I've been fighting with this for the last few days. A few of my entries have external and internal IP's. My internal network is 10.0.0.0/8. When I nslookup pc1.clase.net internally it responds with ...
1
vote
2answers
1k views

How do I get the nc command to end after 2 seconds? [duplicate]

I have to write a maintenance script that iterates over our IPs testing their connectivity to certain services such as nc -sip# mailin-01.mx.aol.com 25. It has a flag -w ... but it's not what I think ...
3
votes
1answer
116 views

Network Connection Type

Is there way to determine the LAN connection type is Secure or insecure ? i.e. the lan cable connected to machine is by IEEE802.1X or not ? EDIT: In ubuntu 13.04, When I configure 802.1x security ...
1
vote
0answers
307 views

Share (masquerade) Internet connection from Debian desktop to a bunch of computers

I need to share the Internet connection of my Debian desktop to some other devices (a Mac Laptop, and an Android tablet). The Debian desktop is connected to the local network via eth0, and the rest ...
3
votes
1answer
994 views

Bind9 — How to find which programs are making which dns lookups?

Using bind9 on a laptop shows lots of nonsense domains when network connectivity is down: Oct 18 19:56:18 lap3 named[1536]: error (network unreachable) resolving './NS/IN': 128.63.2.53#53 Oct 18 ...
0
votes
0answers
41 views

Wireless problems

installed linux mint on a netbook and was working fine until yesterday. When I go to netwrk icon at the bottom, all my ssid are missing and I now "Wireless Network device not ready" in grey.It looks ...
0
votes
1answer
33k views

port opening in linux server

I need to open port 7001 in a linux server ( RHEL 6.3 ). Firewall is not running. [root@hslsaoid2 ~]# service iptables status iptables: Firewall is not running. Please find the netstat -ntpl output ...
14
votes
2answers
1k views

Command to run a child process “offline” (no external network) on Linux

I have a program I would like to test in offline mode without taking down my actual network. This program would still need to connect to local sockets, including unix domain sockets and loopback. It ...
1
vote
1answer
915 views

curl ignores interface parameter

My Ubuntu 12.04 laptop is connected to the Internet by WiFi and to the intranet by cable. I would like to get the content of an intranet site via curl and have tried the following: curl --interface ...
3
votes
3answers
1k views

How to detect IP of given device in same network

I have a very typical situation in which I want to connect an (android) phone to a linux notebook in the same (wifi) network using ssh. The IP's are assigned by DHCP so I know only the one of the ...
1
vote
1answer
762 views

Why is NetworkManager attempting to control an interface script that doesn't exist?

I'm showing hundreds of frequently repeated entries in /var/log/messages that don't make sense. More below the example. Here's an example, which is repeated ad nauseam in the log file: Oct 15 ...
0
votes
1answer
470 views

wireless enabled but can't browse internet

My laptop sees wireless ssid and connects but I get unknown host when trying to ping www.google.co.za, but I get replies when I ping 8.8.8.8, my other machine connected to the same router can surf the ...
2
votes
1answer
63k views

How to connect to Internet in Kali Linux after changing IP address manually?

I have a problem in my Kali Linux. I cannot connect to the Internet after changing my IP address using this command: ifconfig eth0 198.168.198.130 netmask 255.255.255.0 up After this, when I open ...
0
votes
1answer
138 views

How do I verify that the Linux kernel is not freezing when uploading or downloading large data over the ethernet interface?

How to verify if the Linux kernel is doing what it's saying for network interfaces? I have one network interface eth0 which has hardware support to do 1GB full-duplex. I have prepared 2 box. Now ...
1
vote
0answers
201 views

Intercepting packets with bash

I'm wondering if it's possible to detect a packet that comes from certain IP and port(suppose IP 1.1.1.1 and port 80) and has some specific information on it (suppose "<h1>Web ...