Managing and using network connectivity on a unix system

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3
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2answers
2k views

I want to expose “easy” URL's for machines on a home network. Is custom DNS/BIND the answer?

I recently convinced my room mates to cut the cord and go cable free, and they've found it pretty great so far. I'm in the process of setting up a pretty sweet, mostly automated home theater setup ...
0
votes
3answers
642 views

Fedora 18 host cannot ping Windows XP guest

I have my laptop running Fedora 18. I want to run a Windows XP guest using VirtualBox 4.2.6. My configuration seems correct, here is my networking report. Fedora 18 host lo: ...
0
votes
2answers
46 views

can't update with this error messg

I got this message: not enough free disk space.... The upgrade needs a total of 31.8 M free space on disk '/boot'. Please free at least an additional 31.8 M of disk space on '/boot'. Empty ...
2
votes
2answers
2k views

Iptables port forwarding to qemu vm

Is it possible to create an IPtables rule that forwards all incoming traffic on port 80 on the host to port 80 of the qemu VM? Is such a scenario possible with qemu?
1
vote
1answer
332 views

Why does my 3G key blocks my eth0 interface and how to solve this?

I have a linux PC (Debian Squeeze) which is located into a room in another town (I cannot physically access to this PC from where I am) This PC is linked to internet using an internet box. I can ...
0
votes
1answer
357 views

Postfix header_checks

I want to forward a copy of the users email which has the specific subject. I have tried the below settings, able to Redirect that particular subject mail. But I want to forward a copy of that mail to ...
2
votes
1answer
434 views

Explanation of bandwidth management script calling tc

I have some scripts in Linux to manage internet bandwidth, but I do not understand what they do. What is the meaning of the following scripts: tc qdisc add dev $IF root handle 1: htb default 256 tc ...
1
vote
1answer
250 views

Display ONLY IP addresses of currently logged users

I want to get a list of the currently logged users and their respective IP addresses. I tried the following command line: w -s However, the TTY, IDLE and WHAT columns are also displayed. I don't ...
2
votes
1answer
3k views

Could not resolve host error

I'm using Arch Linux and I have a dynamic ip address with the use of dhcpcd. I can access websites through the google chrome but the problem is that I get 'could not resolve host' error when I run ...
2
votes
1answer
4k views

Iptables forward with pptp and openvpn

I have OpenVPN and PPTP installed on a VPS. I'm having a few questions that I can't seem to get a firm answer on. I want to install OpenVPN on 1.1.1.1 (eth0, public IP address) and PPTP on 1.1.1.2 ...
6
votes
3answers
11k views

Check outgoing network traffic

In Ubuntu, how can I check what information is being sent through the network connection, what programs are doing it, and what sites is my computer connecting to? I am not paranoid about security, ...
2
votes
1answer
71 views

switch network on and off of a virtual remote server

I need to perform a testing panel which disconnects a network cable and connect it again on a specific virtual server via a php web page. I found that ip & ifconfig can disconnect a network, but ...
0
votes
1answer
57 views

No internet access for system services; however, browser access works

Unable to reload repos via apt-get, aptitude, or synaptic. Dropbox does not connect or sync. Pithos does not connect to pandora.com. Chrome and Firefox browsers do work fine. I have been unable to ...
6
votes
2answers
20k views

eth0 not being configured automatically

When I start an ubuntu 12.10 instance, eth0 is NOT getting configured. davidparks21@MySqlDB:~$ cat /run/network/ifstate lo=lo When I manually edit ifstate and add eth0=eth0 and service restart ...
1
vote
0answers
147 views

Modifying resolv.conf when when bringing network interface up on system startup

My Linux box currently has a network interface that allows me to connect to a network on a different subnet. I've achieved this by modifying the routing table when the network interface is brought up. ...
4
votes
1answer
1k views

tc on bridge port

I have a 4 port bridge: root@Linux-Switch:~# brctl show bridge name bridge id STP enabled interfaces br0 8000.000024cd2cb0 no eth0 eth1 ...
1
vote
0answers
982 views

I have a route to the network but from the traceroute output it doesn't leave the server

I have an HP-UX box and I'm trying to determine why a host can't be reached. I'm trying to reach the host 10.32.13.146 root@hp-ux:/root # traceroute -I 10.32.13.146 traceroute to 10.32.13.146 ...
4
votes
4answers
38k views

Ubuntu: How to configure DNS servers in /etc/network/interfaces correctly for resolvconf?

All examples I have seen of configurations (/etc/network/interfaces) showed that you configure an interface and then underneath that gave the dns-* lines such as: auto eth0 iface eth0 inet static ...
0
votes
1answer
134 views

What are the other congestion control algorithms specially designed for lossy Wireless Networks like LTE and WiMax?

I am trying different congestion control algorithms for getting maximum throughput and minimum delay across my setup for TCP flow.Please suggest other available algorithms apart from Veno, ...
0
votes
1answer
116 views

Problem in connecting server to Internet

I just have setup a Linux server. But currently I am having problem in connecting to the outside world. I am not able to do wget,apt-get or ping. Here ar some relevant details: $ping google.com ...
5
votes
1answer
268 views

Ways to give a process “idle” network priority

When I'm playing a game, I don't want Dropbox taking hogging my network connection. I have been able to noticeably reduce my latency by turning it off while playing. The same is true to a lesser ...
0
votes
1answer
571 views

How to troubleshoot high kernel time (high network usage; high interrupts)

I've noticed that I have high kernel time when doing a lot of network traffic in Linux. I also noticed that 45% of my CPU is spent doing interrupts. How can I further troubleshoot this?
3
votes
1answer
14k views

Cannot reach outside network or IP after upgrading to Ubuntu 12.04

I am running Ubuntu 12.04 on my server but since the upgrade from 10.04 I can no longer reach any outside sources of the server. I can SSH into the box, but from inside here I can not reach anything. ...
0
votes
1answer
4k views

OpenSuse 12.3 keeps renaming network interfaces?

After installing OpenSuse 12.3 (x64) on a server box with a single (onboard) NIC (assigned to eth0), all works fine so far (static IP, static route, no "Network Manager" - just the good old way). ...
4
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0answers
199 views

To what extent does LXC manage configuring the network interface in a container?

In the LXC config file we can specify an IP address for a container: lxc.network.type=veth lxc.network.link=br0 lxc.network.ipv4 = 10.1.0.35/16 lxc.network.flags=up lxc.network.hwaddr= ...
2
votes
0answers
280 views

Network in LXC not forwading through a bridge

I've got an LXC container, on the host I've got a bridge between the LXC container and eth0. The LXC container can ping it's Host 10.1.0.5, but can't ping the gateway of 10.1.0.2. The host is able to ...
2
votes
0answers
2k views

Using a bridge, an LXC container can't ping router, but the host OS can

I've got a virtual machine running under virtualbox, and in that virtual machine I've got an LXC container I'm trying to bridge to virtualbox's NAT interface: ------------- ----------- ...
1
vote
1answer
162 views

Communication to device is lost when network starts on boot up?

I have an application that opens a socket on port 4444 to a device (/dev/linkToDevice). The "linkToDevice" is a link to ttyUSB0. The application is a c++ program of which is now a daemon and runs at ...
3
votes
2answers
2k views

Use eth interface to connect to a router and wlan for the internet

I am currently trying to configure a router to which I connect to (to its web interface) using an Ethernet cable through the eth0 interface. That router doesn't have access to the internet. Now, I ...
5
votes
2answers
4k views

Routing for multiple uplinks/providers

I have a PC with two internet connections. The first one is an Ethernet interface to connect to my local network and access internet via my router. The second one use a GSM modem to connect with ppp. ...
3
votes
2answers
6k views

Extra bridge interfaces get added automatically

I have a bridge set up between eth0 and br0, the bridge works fine, but sometimes, for unknown reasons and circumstances, I keep getting these off vethXXXXXX interfaces added to the bridge. When this ...
0
votes
1answer
187 views

Make application listen to hosts under a different gateway

Network Structure A typical college network. Different Hostels connected through LAN. All hosts in a hostel use the same gateway. I can directly communicate to hosts in other hostels using their ...
31
votes
7answers
10k views

Block network access of a process?

Is it possible to block the (outgoing) network access of a single process?
1
vote
2answers
2k views

How to transparently monitor SSH access/network traffic in Gentoo/general linux?

What's the most effective way to monitor SSH access in Gentoo Linux? My Gentoo box is operating locally behind my broadband router. I have SSH port forwarding on the router and a DNS entry pointing ...
1
vote
1answer
88 views

Enforce strict outbound ports (or ranges) for protocol

Is it possible to narrow the allowed range of outbound ports that can be used for a specific protocol (e.g. HTTP(S))? I understand that, by default, the system will randomly allocate any available ...
1
vote
3answers
527 views

Packet analyzer to intercept and filter incoming traffic before any client app

I am curious if most Linux distros make it possible to intercept incoming network traffic as soon as it enters the system and filter its content based on some rules before any other client can use it ...
1
vote
0answers
194 views

No AirPlay in XBMC on EeePC (Debian)

I have a Asus EeePC (900 model I think) and I've installed Debian 6.0 on it. I've managed to get WiFi working on it and I've installed XBMC. It's working with our NAS drive on the network but for some ...
2
votes
1answer
93 views

Custom application running on embedded device - do I need to register my listening port in /etc/services?

I have written an application that will run on an embedded device. The installation is very minimal and uses busybox and not many other things. Part of the software includes a listener thread that ...
0
votes
1answer
187 views

Local host always being added to /etc/hosts.deny when trying to SSH

I have a rather odd problem with my server. For some reason the local hostname for my workstation keeps getting added to the /etc/hosts.deny and when I try to SSH I get: ssh_exchange_identification: ...
0
votes
0answers
707 views

Tools to find OpenVPN UDP packet corruption

Are there Unix tools to troubleshoot UDP packet corruption? I'd like to avoid writing my own... I think ping might report when a packet is corrupted, but it doesn't really seem to have options ...
0
votes
1answer
163 views

Samba connection slowness after ip change

we have encountered with a problem when we chaged the samba server's ip address. There are so many OS varies from Windows,GNU/Linux, Solaris and IBM. The samba server is running on SOlaris. And all ...
26
votes
1answer
802 views

Why does it take up to several minutes to clean a listening TCP port after a program dies?

If I kill a program that is listening on a TCP port, it takes up to several minutes until the port is reclaimed by the system and usable again. I've seen several Q/A mentioning this phenomenon, but ...
5
votes
1answer
3k views

Very slow response from localhost when pinging

Networking is working fine on my gentoo machine. One connection is made, everything works fine with normal speed. But it is slow to wake-up : starting up connection is taking time. Even pinging ...
1
vote
1answer
9k views

Use of /etc/sysconfig/network-scripts/ifcfg-eth* files

What's the use of /etc/sysconfig/network-scripts/ifcfg-eth* files ? In some cases ifconfig lists the interface eth0 but I don't find the corresponding ifcfg-eth0 file whereas in other instances if I ...
5
votes
2answers
5k views

Use an USB tethered phone as network adapter

I am running CentOS 6 and was able to tether my HTC phone using a proxy called proxoid . This allows me to redirect HTTP. But how do I redirect the entire TCP traffic, e.g. if I need to setup openvpn ...
2
votes
1answer
490 views

Solaris 11: How to use ILB to create HA loadbalancer across two backend servers?

I'm attempting to use Solaris 11's ILB to create a loadbalancer across two backend DNS servers. Here's my requirements: Two external IPs: .XXX.YYY, .XXX.ZZZ - these are the DNS IP's that our clients ...
3
votes
2answers
4k views

Guest OS Ubuntu 12.04 no network connection

Recently added a new *.VDI image with Ubuntu 12.04 to my existing VirtualBox. The machine hangs with a "Waiting for network configuration" error, eventually times out after 60 seconds and boots in ...
2
votes
2answers
147 views

Remote access SSH problem

I have been asked to setup a lab with 1 PC (fedora 18 OS) and 4 SGI (IRIX 6.5 OLD OS). I am using a switch to connect them to university's network, and I asked tech guys to assign static IPs to them. ...
14
votes
4answers
2k views

Is there a top-like command that shows the network bandwidths and file accesses of running processes

For example, we'd like to see: PROCESS IF TX RX FILE(regular) R/W prog1 eth0 200kB/s 12kB/s -- -- wlan0 12kB/s 100kB/s -- ...
-1
votes
2answers
5k views

Unable to connect to remote host using ssh

I have recently installed Fedora in my system. But I am facing some problem in ssh login from remote machine. I am able to login in that system but every time its requires me to login using GUI in ...