Managing and using network connectivity on a unix system

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Can't access my apache server from outside LAN (Raspberry Pi)

I know this question was asked a lot, but unfortunately none of the posts really helped.. I'm trying to set up an Apache server on my Raspberry Pi. I managed to set it up correctly I think, but I ...
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2answers
41 views

How to tar, split, pipe, untar over ssh

I'm copying large files over LAN, and I've noticed that with doing one ssh pipe, I can get around 10MB/s transfer speed. However, if I shoot off four of those at the same time, I get around 40MB/s ...
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17 views

How do you create an ip alias using iproute utils?

While reading the O'Reilley book on Apache Web Server, they gave an example on using ifconfig to set ip aliases on an interface: ifconfig ep0 192.168.123.2 ifconfig ep0 192.168.123.3 alias netmask ...
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1answer
42 views

Why is my DAD slow?

The last few boots of my Arch Linux, I noticed I had no network access. I'm using a netctl profile to give my adapter a static IPv4 address, which by itself works fine. So I had a look at the logs, ...
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1answer
12 views

What is a hotplug event from the interface?

According to Debian Network setup document allow-hotplug <interface_name> stanza in /etc/network/interfaces file starts an interface when the kernel detects a hotplug event from the interface. ...
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1answer
20 views

Connect through different interfaces to the same server

i have two pppoe interfaces - ppp0 and ppp1. I would like to reach the same server on both interface. I added the desired ip address to the route table: route add 10.88.40.13 ppp0 And I could ...
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3answers
55 views

One-liner for getting an IP address of an internal DNS name?

I have an internal DNS name for which I'd like to get the IP address. Is there a nice Bash one-liner I can issue to convert internalip1.mydomain.com into 10.10.10.10?
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13 views

How can I configure multiple tap interfaces for a single KVM virtual machine

I am trying to setup a VM using Linux KVM for a F5 BIG-IP VE deployment (used in a lab) ...
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0answers
7 views

Transport keyboard/mouse events to a keyboard/mouse-less remote host

I want to send keyboard and mouse events from a small ARMv7 computer board to a remote one, which has no keyboard nor mouse. I'm planning to send these events on a locally implemented CAN bus. The ...
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1answer
16 views

I need dhclient to flush IP address/routes when link goes down

I am running one Ubuntu Server 14.04 with network configuration using /etc/network/interfaces and so ifup/ifdown scripts. I realised that if I configure one interface in DHCP mode, then I unplug the ...
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1answer
31 views

How do I run a program without network access? [duplicate]

I am making a program that scrapes information from some web services. I want to test how my program reacts when it can't reach the web service, like if the web service is down or if the local ...
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14 views

how do I disable the firewall through YaST?

The fine manual states: The Start-Up section defines how your firewall will start. You can either have the firewall start automatically when booting (recommended), or you can set the firewall ...
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1answer
31 views

what is “rfc3442-classless-static-routes” in /etc/dhcp/dhclient.conf

I am trying to debug DHCP on my laptop (I am using dhcping and dhcdump to see what the DHCP server sends back). Following is my /etc/dhcp/dhclient.conf. option rfc3442-classless-static-routes code ...
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2answers
80 views

How to print from a given range of ip addresses every class-c with the last octect replaced by an asterisk

example: I have a range from 10.0.100.0 to 10.0.224.0 and I want the output like this: 10.0.100.* 10.0.101.* 10.0.102.* and so on
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0answers
29 views

can't connect to remote host with MySQL…firewall problem?

I've granted privileges to thufir for remote access through the shell (correct?), but cannot seem to actually connect. The router firewall has SPI to off. I've disable the IPv6 firewall on the ...
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1answer
14 views

WiFi only connects to my router, not to any other access point

I have a Raspberry Pi 2 with a WiFi USB dongle. I don't know the brand or model, I got it for free with my Xtreamer Mk1 in 2009. My Windows 7 PC installs some generic Realtek RTL8191SU WLAN adapter ...
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0answers
15 views

eth0/usb0 bridge breaks after removal and replacing android phone

I'd like some help with a networking bridge issue I've run into. I'm trying to make a bridge with eth0 and usb0 (my android phone). After running the brctl commands the bridge works wonderfully. But ...
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0answers
10 views

shared filesystem with offline access

I would like a shared filesystem with offline access. I have two machines. One is a light laptop with a small amount of SSD storage that I carry with me. The other is a stay-at-home computer with much ...
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1answer
35 views

Test for open TCP port in bash script

I want to delay the script execution until a certain server process is ready, which it is once it accepts incoming TCP connections. How do I test if a local TCP port is open (I get a SYN/ACK answer)? ...
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2answers
159 views

Using bash's `/dev/udp`, how would I know if the port was open?

I do not have access to netcat or nmap so I'm trying to use bash and the /dev/udp/ special files to test ports. I could do something like: echo "" > /dev/udp/example.com/8000 But $? is always 0 ...
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0answers
14 views

Dropped connections with b43 driver using Broadcom BCM43228 wireless chip on Arch Linux

I managed to get my wireless working with the b43-firmware package in the AUR and for at least a month it worked perfectly. However, recently the internet connection has been dropping out. I'm ...
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0answers
9 views

Fair traffic classification using TC

I want to apply a qdisc I developed on myself (quite similar to netem. Think netem.) to several IP-addresses using the filter classifier. No problem this far, I could do so using the prio qdisc or HTB ...
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0answers
33 views

Make docker containers accessible via vpn

I have three physical machine A, B, C, each of them has docker installed. I want to install openvpn server on machine A, and install openvpn client on B and C. B and C will connect to A. I want to ...
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0answers
23 views

how to set a route and firewall for a static ip

These directions on setting the static ip address for vicidial seem at once very specific and overly broad: Type 'yast lan' and press ENTER Optionally, you can type 'yast' and navigate to the ...
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1answer
54 views

why can't I ping Google with a static IP address?

I'm trying to install vicibox, an OpenSUSE distro which includes Asterisk. The fine manual says to set a static ip address with yast lan. What's the difference between: ││[ ] Change Hostname via ...
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11 views

static ip address in yast

I think that I set the FQDN for the server in yast. How do I set the static IP address with yast? I go to network devices => network settings, see my NIC: YaST2 - lan @ arrakis Network Settings ...
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1answer
17 views

How does tcp communicate back to the application? [closed]

Are there standard sytem calls to send data to TCP? And back? How does TCP tell the application to send more or less?
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0answers
16 views

how do I set a hostname in yast?

how do I set the hostname, FQDN, in yast? I ran yast => network devices => network services => hostname/DNS: YaST2 - lan @ arrakis Network Settings ...
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1answer
22 views

How do I limit inbound and outbound bandwidth to and from a specific host on CentOS

As the title says, I am trying to limit inbound and outbound bandwidth to and from a specific host on CentOS. The reason is that this host consistently uses a large amount of bandwidth and this needs ...
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2answers
18 views

mknfsmnt fails with “System call error number -1”

This system is part of a cluster and the other node mounts the nfs share successfully. This is currently the active node which means it has a secondary service ip address. I think this is related to ...
2
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1answer
73 views

Understanding why such a discrepancy in network transfer?

Summary: I can't understand a peculiar discrepancy in network transfer. Why is there such a discrepancy in syncing from one machine to the other and vice versa? Also: Given the maximum network ...
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1answer
31 views

Why can `lsof -i` not show an open connection which `netstat -n` lists?

A strange situation. I started telnet 0 8081 and lsof -i (run under root) doesn't list this connection, but netstat -n does. Why can this be?
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0answers
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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 ...
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1answer
22 views

Sending messages to another user over network

This one is similar to Sending messages to another user except that I want to accept messages over network. If there is a way to just unblock the port to receive messages, that would be fine. If ...
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0answers
21 views

Local system doesn't forward to intended port defined in OpenShift proxy app

I've set up a proxy server via OpenShift based on this tutorial and used a few days by forwarding my local system's ports to remote app's ports: $ rhc port-forward AppName The result in the proper ...
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2answers
36 views

How to setup routing tables to connect two subnets

How do I setup my routing tables to allow traffic between two subnets I have a gateway box with two NIC's 1st NIC [eth0] is connected to my outgoing network side and DSL modem and has subnet ...
1
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1answer
22 views

Is it possible to add some 'PXE Network Boot' option to GRUB?

This is an example of my available GRUB menu boot options: 1 menu label ^ 1) Xubuntu 14.04.02 LTS 2 menu label ^ 2) Windows 7, x86 & AMD64 3 menu label ^ 3) Windows 8, ...
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33 views

Ip route: Routing with two interfaces (only one connected to Internet)

I have this problem: I have a laptop with WiFi and eth. The WiFi is connected to the internet and has the following config: 192.168.1.100 and 192.168.1.1 as gateway The eth is connected in this way ...
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0answers
9 views

All packets after the first one on tun0 are dropped

I'm trying to run the Aventail VPN 10.7.1.449, and it doesn't work since every packet after the first one is getting dropped: tun0 Link encap:UNSPEC HWaddr ...
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4answers
87 views

Shell Scripting: Proper way to check for internet connectivity?

I found scripts that say they check for internet connectivity. Some check the ip address if the interface is connected BUT it does not check for internet connectivity. I found some that uses ping like ...
1
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1answer
35 views

Missing network list in menubar after using airmon-ng

After using airmon-ng in kali linux the list of available networks is missing in the menu bar at the top. Can anyone please tell me how to "reactivate" it? When i use iwconfig it shows up an entry ...
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0answers
39 views

Problems forcing Debian to obtain IP from predetermined server address using DHCP from nameserver on network

I am having trouble getting my Debian server to change the address where it requests its IP address. I currently have two routers. My primary distributes IP addresses to various machines on the ...
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1answer
39 views

NIC statistics explanation (ethtool -S eth1)

What is the meaning of each of the results from ethtool -S eth1 command? For example, when I used ethtool -S eth1, I got something like this: >root@localhost ~]# ethtool –S eth1 >NIC ...
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12 views

why do I have so many open socket handlers and netstat DGRAM entries?

I run on a RPi (Raspbian 3.12.35+ #730 PREEMPT Fri Dec 19 18:31:24 GMT 2014 armv6l GNU/Linux) a daemon in Python 2.7.8 which queries various APIs via requests and provides itself an API for another ...
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2answers
43 views

Cannot access internet through OpenVPN

I have set up an openvpn server, generated a certificate and downloaded it to my client machine. After importing the client.ovpn file in the network manager, I can still ssh into the server itself, ...
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51 views

SSH server listening on multiple ports with passwordless access not allowing connections to second port

I have my Synology NAS running an SSH server listening on the default port 22 and I set up passwordless authentication with a public/private key and a passphrase: From sshd_config: ...
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0answers
15 views

Connected to wifi but no internet access

Unable to be pinged from other machines (other machine returns 'Request timed out') Unable to ping the router or any other device (returns 'destination Host unreachable) Unable to use the internet ...
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1answer
39 views

make my Debian laptop switch autoamtically to a backup connection

I have a laptop with Debian OS installed under it. It is initially connected to the internet using an Ethernet cable (via a modem) and I want to automatically switch to a backup wifi connection (which ...
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0answers
10 views

How to restrict access of a process to specific ports?

How can I restrict access of a process to use only specific ports, or block it if it uses non-allowed ports?
2
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1answer
28 views

Secure way to allow any user to run programs in specific network namespace

I have a cell modem connected to my server that I want to use as a means to get notification emails out when the landline dies. To nicely separate normal network access and this exceptional cell ...