Managing and using network connectivity on a unix system

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7
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147 views

Trying to understand Auto reconnect WIFI method

I found this method of reconnecting the WIFI dongle from this post. But, I want to be clear on how it works, before I try and implement it. Go to /etc/ifplugd/action.d/ and rename the ifupdown ...
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29 views

Why doesn't NAT reserve ports from the machine's TCP and UDP port pool?

I made two experiments. This is the network for both of them: [private network] [public network] A -------------------- R ----------------- B 192.168.0.5 192.168.0.1|192.0.2.1 ...
4
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81 views

Disable networking only inside of a single terminal

I want to run a command in the terminal to disable networking, just in that terminal. How can that be accomplished? I'm running OSX. Note: I only want to disable the networking in that terminal. ...
4
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41 views

Queuing disciplines are per-interface, what happen with interfaces using same device?

I have read about queuing disciplines here http://lartc.org/. I understand that for instance band 0 of pfifo policy is prioritized over band 2 within same qdisc, but what happen when i have ppp0 and ...
4
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176 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= ...
3
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48 views

Linux Routing Question

I was wondering how it would be possible to have multiple IPv6 default gateways on CentOS linux. I currently have two interfaces with IPv6 (venet0 and tb0), both with different blocks routed to them. ...
3
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355 views

Is it possible to throttle upload bandwidth per `IP` basis using `tc`, `htb` and `iptables` ? (Download limitation not required)

Problem I've searched internet like anything but couldn't find much about limiting upload. The solutions given are not limiting IP basis like this one but LAN as a whole. +-----+ ...
3
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16 views

Radiusd(freeradius): User only for a special client

Is it possible to restrict a user from the "users" file to a special client? I try to use one radiusd server for two wifi access points but I will use one user credentials only for one access point ...
3
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64 views

Is there a thing like “veth”, but without link-level headers?

When I use separate network namespace, I often set up networking there using veth: ip link add type veth ip link set veth0 netns 1 ifconfig veth1 192.168.60.2 ip route add default via 192.168.60.1 ...
3
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68 views

Trickle not behaving as expected

I'm using Ubuntu Trusty 14.04 64 bits. I've installed trickle network shaper from repositories and I performed some tests: No limits I executed this command to test somehow my network download ...
3
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64 views

delay in IP route deletion

(Apologies if this is the wrong StackExchange for this question, but there does seem to be some confusion regarding appropriate targeting of IP networking questions) I am very much a network newbie, ...
3
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115 views

tc cbq doesn't work (no traffic limitation)

I've been trying to use cbq weight attributes after HTB failed to do so. I've tried using a command set I've found in an example just to verify it works (HTB works fluently) Here are the commands I ...
3
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798 views

What does `NO-CARRIER` and `DOWN` mean for a wireless interface?

I have a remote server and I log output of certain commands while the server cannot access the internet. It uses a wireless interface to connect to the internet. In a working state the output of ...
3
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0answers
76 views

Configuring pulseaudio for receive mode

I am working on a project where I'll be running PulseAudio in receive mode on my raspberry pi. As for the server side, we've been writing a custom application on windows that will send an RTP audio ...
3
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0answers
2k views

Unable to start network, <IP> is already in use for device eth0, but its not

A wierd issue after we migrated some of our servers to a new DC. We assigned new IPs to all the machines and all the servers are working fine except one. It is not picking up the new IP address and ...
3
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0answers
43 views

Log if no network

I have a router with OpenWRT. I noticed that sometimes (during night time) I have no internet connection. How can I log when this happens?
3
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150 views

AppArmor Profile: Deny internet access

I want to deny the internet permission for some applications. Therefore, I tried first to deny the internet permission for ping, but it doesn't work. Here is the profile of /etc/apparmor.d/bin.ping ...
3
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0answers
992 views

Linux - Only first virtual interface can ping external gateway

I created 3 virtual interfaces with different MAC addresses all linked to the same physical interface. I see that they can successfully arp for the gateway (gw) and they can ping (the request is ...
3
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243 views

AIX NIM Master replicate / sync fails to an Alternate Master

I am getting a error when I try to replicate / sync my NIM database and resources to an Alternate NIM Master newly created in my environment: error replicating resources: unable to ...
3
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181 views

Raspbian: how ifplugd works on lo and other interface

On my raspbian, I'm wondering why ifplugd (link detection daemon for ethernet devices) is also running on the lo the loopback interface. The ps command displays: /usr/sbin/ifplugd -i lo -q -f -u0 ...
3
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470 views

How to setup networking for Linux Mint - VM when host machine uses a PAC file

My host is a Windows 7 x64 machine. The office network uses a PAC file for the LAN settings. So, under Internet Options -> Connections -> LAN Settings, I have Use automatic configuration script with ...
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1k views

I can SSH and HTTP, but not ping or access particular UDP services over my LAN

So I've encountered a weird problem when trying to set up a Linux server running a variant of CRUX Linux. I am trying to configure it to be a Teamspeak server, but no clients can connect. The ...
3
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2k views

SCTP support for Linux kernel 3.3.4-5.fc17.x86_64

I'm using Fedora 17 64-bit version, with Linux kernel version 3.3.4-5.fc17.x86_64. I installed lksctp using yum. sudo yum install lksctp-tools.x86_64 When I try to run sctp_status -H 127.0.0.1 ...
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731 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 ...
3
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706 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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7 views

Umount network drives with systemd before shutdown

My shutdown takes quite a long time (I'm on Debian 8.1) and I found out that it can be fixed by unmounting the network drive before shutting down the system. Apparently the network gets disconnected ...
2
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34 views

More than 255 Linux GRE tunnels

Is it possible to set up more than 255 GRE tunnels in Linux? It seems that 255 is the default maximum, but is there any way to increase the limit?
2
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0answers
46 views

Difference between MTU for a route and MTU for an interface

There is a server I connect to over the WAN and somewhere over the route there is packet loss unless I set the interface MTU to 600: ifconfig eth0 mtu 600 Doing this causes problems with ...
2
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13 views

Wi-Fi Sabrent PCI-8021N Linux Debian Jessie _x86_64 using ralink firmware/desktop

I've been trying since Thursday to get a sabrent card to come up and show what wifi networks are available. I'm in midtown Atlanta...so seems there should be 1 or 2 networks showing. The card's power ...
2
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0answers
37 views

check the current backlog queue size

The sysctl netdev_max_backlog sets a limit to the maximum number of packets allowed in the kernel's backlog queue. Is there a way to check the current queue size (i.e., how many packets are currently ...
2
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0answers
32 views

Converting a raw print data stream containing PCL commands to PDF

I have a program that sends raw print data through samba to typically PCL compatible printers. The program is written so basic PCL commands control how it prints. When sending it to the printer it ...
2
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0answers
70 views

How to find out the wifi sensitivity (RSSI)

I want to be able to get the received signal strength indication from my computer's wifi interface, ideally as expressed in dBm. This article explains what I am after.
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79 views

Binding nonlocal address on NetBSD

This is not a programming question, but a question about NetBSD. Linux, FreeBSD and OpenBSD have mutually exclusive but similar interfaces to allow binding the local end of a connection to an address ...
2
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0answers
203 views

Force IPv4 over IPv6 only for certain addresses

I'm currently running Debian 8 and I'm trying to force applications like Google Chrome to use IPv4 over IPv6 only for certain sites. My ISP natively offers IPv6 and it's amazing on all websites that ...
2
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0answers
162 views

Running a systemd service file after the network is up to bypass an OpenVPN default gateway

I would like to add a static route using a systemd service file on system boot. I have a DMZ network on a separate 192.168 class C network reachable via my default gateway. I also use OpenVPN to ...
2
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0answers
154 views

Why is dhclient making DHCP requests on a static interface?

I'm setting up a new Debian system. I have a static IP configured on an interface in /etc/networks/interfaces like so: # The loopback network interface auto lo iface lo inet loopback # The primary ...
2
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0answers
71 views

How to monitor UPnP communication?

My Computer is connected to router that supports UPnP, however it's not the last router on the way to the WAN. So, mapping there has no effect. I've got VPS and I've made a VPN network (computer ...
2
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0answers
244 views

What are bogus file nlink values?

I am using files from a SMB share on my Raspberry Pi, running Raspbian. Whenever I access those files, I get the following message in my syslog: CIFS VFS: bogus file nlink value 0 What does that ...
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35 views

Automate a gratuitous ARP every x seconds

There may be another issue here, so any other questions or comments are welcome. I have a CentOS 6.6 VM running under VirtualBox. It is connected to a GNS3 topology using a UDPTunnel. Everything ...
2
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0answers
345 views

vpn l2tp connection on ubuntu 14.10

I am using Ubuntu 14.10 and I need to create a VPN L2TP connection. I installed strongswan, as suggested by this answer, but now I don't understand how to configure the connection. The connection ...
2
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0answers
64 views

debugging iptables when tunneling one VPN through another

I seek to tunnel one SSL VPN (F5, running on my debian laptop==client) through another (OpenVPN, running on a debian linode==server), but lose all client networking (including, e.g., ping) after the ...
2
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0answers
126 views

Correctly populating wpa_supplicant.conf from iwlist scan results

I am wondering how I can tell that my wpa_supplicant.conf file is both sufficient and valid. When running iwlist scan outputs ESSID:"wifi" Protocol:IEEE 802.11bgn Mode:Master Frequency:2.412 GHz ...
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217 views

Is Traffic control inside namespace on ports created by OpenvSwitch supported?

I am trying to limit the bandwidth of an interface inside a namespace using tc without much success. Seems it's not supported according to ...
2
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0answers
712 views

ping localhost sometimes fails with sendmsg: Operation not permitted

I have a problem with network adapter (i think) , look I trying to ping my self and got a error sometimes, how this can be ? First time in my life i see this. # ping 127.0.0.1 PING 127.0.0.1 ...
2
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93 views

Linux - On boot do push-button-connect to strongest wireless

I'm trying to configure linux (in this case CentOS) to automatically connect to the nearest WiFi via "push-button-connect". This micro computer has no keyboard or display, so the goal is to hit the ...
2
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231 views

Connecting to two ISP in local network using two different network

We have two ISP 1. BSNL (INDIA), 2. Airtel (INDIA). we getting Bsnl internet through D-Link DSL 2750U modem which holds the IP 192.168.1.1, Airtel internet modem with 192.168.2.1 IP address, Here it's ...
2
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0answers
40 views

Same Wifi names keep messing with connection

I just got a RasPi and I'm looking to replace the Windows PC that's doing the routing job. (To save electricity) What I'm trying to do with it is make it connect to a wifi network using it's bssid(or ...
2
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0answers
167 views

Making static routes persist after a reboot

I have two VLANs (default vlan and vlan 5 for voip). I have 2 interfaces, one for each VLAN. My route table looks like this right now: Destination Gateway Genmask Flags Metric ...
2
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306 views

How to exclude LAN traffic with iptraf-ng?

I'd like to use iptraf-ng to see how much data my machine is sending/receiving from the Internet, but I want to exclude traffic on my LAN as I am only interested in data going off-site. I have ...
2
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0answers
440 views

VirtualBox guest machine as a nginx host

I have VirtualBox 4.3.12 with Fedora 20 and nginx 1.4.7 installed. Machine has Bridged Network interface and pings can be done both ways: from host machine (Windows 7) using ping 192.168.0.15 ...