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Questions tagged [networking]

Managing and using network connectivity on a unix system

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1answer
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Shared Internet Issue

I have a laptop running debian 9 with a wired NIC and a WIFI NIC. I want to connect the wired NIC to a CCTV network which the DVR has an ip 10.1.18.101 subnet 255.255.255.0 and no gateway. I can add ...
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0answers
4 views

Script to add multiple routes in single machine for differnet virtual Nic

Script to add multiple ips for different NIC in single linux machine. For Example a linux machine having more than 50 nic like eth0 ,eth1,eth2,...eth50. This machine actually Virtual machine in ...
0
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1answer
19 views

Any way to swithc default rout to vpn when connecting?

I'm using gnome NetworkManager and connectiong via openconnect to a vpn server, but my default rout is not changing when i'm connected and all traffic goes around vpn. Can i somehow make ...
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0answers
19 views

How can I make a router using CentOS 7

Route a print server I am asking this community for some advice on routing using a CentOS 7 server. This situation is as follows: I have an external print server (let’s say it’s on subnet 10.0.0.0/...
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0answers
20 views

Multiple Network Cards with the same Inet Address and Socket connections

I am currently working on a program that needs to have multiple Wireless Network cards that can communicate to different devices at the same time on the same port. Currently, when I try and connect to ...
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1answer
14 views

New Intel i350 NIC not detected by system, but appears in lspci - Possible Intel IGB issue?

I'm running into an issue where a new network card isn't being automatically detected by the OS. I recently purchased an Intel I350 gigabit network card. I have purchased this card before and I have ...
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0answers
23 views

How can I limit engagement with a large office LAN?

I work in a large office building with hundreds of other computers on the same LAN. I don't have any reason to communicate with most of these computers, and when I do, it's always on an "opt-in" basis ...
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1answer
25 views

openSUSE - can't ping to internet

I have a fresh openSUSE server. I can ping it from the LAN and the server can ping the client. But the server is unable to ping any website from the internet? I already entered the correct gateway ...
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2answers
32 views

Telnet - how to verify why a port is blocked?

We have linux machines with RedHat 6.5 operating system. When we try to telnet to localhost on port 8182, we get connection refused: service iptables status Firewall is not running telnet localhost ...
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0answers
9 views

Proxy setup between a private and public [on hold]

I have two servers: Private Server with IP: 172.16.0.2 Public Server with 172.16.0.3 (private IP) and x.x.x.x (public IP) What I want to achieve is: Incoming communications to Public IP (x.x.x.x) ...
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0answers
34 views

Connecting to home SSH server behind a vpn with home public IP [on hold]

I have a SSH server hosted on a desktop at home and it is also connected to NordVPN through OpenVPN. Internet --> Modem ---> Router ----> Desktop/SSH_server Everytime I have NordVPN on I am unable ...
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1answer
20 views

How do you count the number of hops?

I'm trying to connect to the GAN (Internet) and my final network node is 10.200.0.1 How do I count the number of Hops to reach this final network node? I've tried traceroute 10.200.0.1 But it only ...
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1answer
20 views

Setting 'DF'-bit in ip-header inside pcap file

There is some .pcap-file with fragmented ip traffic. I replay this file with tcpreplay, but also I need to replay it with DF (don't fragment) bit set in some packets. I supposed that tcprewrite will ...
1
vote
1answer
30 views

Debian 8(Jessie) started before DHCP server results in no network connection

Recently we got a power outage and our debian 8 Raspberry Pi did not reconnect to the internet. We noticed that our DHCP server was very slow to start > 5 min. In this time the Pi was already up and ...
1
vote
1answer
46 views

Wireless networking on Debian

I've used Fedora, CentOS, Ubuntu and Arch and never been totally stuck for wireless networking. I'm using Debian with KDE and I'm stuck. 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue ...
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3answers
92 views

How Fix this Issue rescue-ssh.target is a disabled or a static unit, not starting it

*uname -a Linux xxxxxx 4.18.0-kali1-amd64 #1 SMP Debian 4.18.6-1kali1 (2018-09-10) x86_64 GNU/Linux *apt list openssh-server -a Listing... Done openssh-server/kali-rolling,now 1:7.8p1-1 amd64 [...
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1answer
18 views

Can't ping anything when IPV6 is disabled

When I disable IPV6 on my Debian install I can't reach the internet, and whenever I ping anything I get ping: unknown host ... This is how I am currently disabling IPV6 net.ipv6.conf.all....
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2answers
74 views

Linux network configuration: A can of worms?

I have deep problems with my LAN adapter configuration, using Debian 9.5, so I'll describe what's happened then raise my question. --First Step: While installing Debian 9.5, I gave the address I ...
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0answers
21 views

Q: (Linux Networking) [closed]

Is there any a list of commands to do Linux Networking? Also is there a way to do Subnetting in Linux? Can anyone recommend me a good Website or YouTube video?
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0answers
20 views

Is there a way to connect noip2 to my Kali Linux apache2 over the network using Ngrok

Is there a way to connect noip2 to my Kali Linux apache2 over the network using Ngrok or Vpnbook? I created a dynamic DNS hostname in noip2 and I modified with the ip of ngrok. when I used over ...
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0answers
62 views
+50

Why IPv6 connectivity on OpenVPN network failed after short time?

I use OpenVPN TUN network. IPv4 works fine. But I have added support for IPv6. I have a problem with IPv6 connections. IPv6 works fine only for short time. When I ping tun0 IPv6 address on my VPN ...
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1answer
43 views

How exactly are NetworkManager, networkd, netplan, ifupdown2, and iproute2 interacting?

I am learning about Linux networking on my Kubuntu 18.04 workstation, and I see there that both NetworkManager and networkd-dispatcher are running: oleg@eclectic:~$ sudo ps -ef | grep -i net root ...
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0answers
9 views

Can't connect to WiFi with WPA-EAP

I'm trying to connect to a WiFi with WPA-EAP, but it always fails with error: failure to add network: invalid message format Full log from journalctl: NetworkManager[668]: <info> device (...
1
vote
1answer
21 views

I'd like to setup a bond0 interface using 2 eth devices in CentOS 7 in VirtualBox?

I would like to set up a CentOS 7.x VM inside of VirtualBox so I can experiment with bonding interfaces. How can I set up this VM so that it has the following interfaces: eth1 (private network - 192....
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0answers
28 views

Block destination IP if traffic exceeds a set amount of MB. Iptables? [closed]

Environment: - Ubuntu Server 14.04 LTS - Webserver: NGINX Goal: - Block an IP after too much generated traffic. I am open for suggestions how to do this. As an exfiltration detection/prevention ...
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1answer
27 views

ssh to docker container breaks after 45 seconds

I have docker running on a synology nas. The nas has a private network (172.17.0.0/16) where docker places the containers. It also has a public facing interface on my lan, call it 10.11.12.10/24. ...
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2answers
29 views

dhclient command does not allocate ip address to my interface

So I was trying to access a website through my browser but I couldn't. So I issued the ifconfig command to see if there was something wrong with the IP address I noticed that the interface enp0s3 ...
0
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1answer
26 views

NIC interfaces and physical ports

I have a physical server with 4 network ports and 3 network cables attached to port1 , port2 and port3. OS is Centos 6 and it has 4 files eth0, eth1, eth2 and eth3. Are these files matched with ...
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0answers
6 views

the behaviour of forward chain in iptables wrt to docker

https://docs.docker.com/v17.09/engine/userguide/networking/default_network/container-communication/#container-communication-between-hosts says: Communication between containers Docker will ...
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0answers
20 views

Subdomains get NXDOMAIN on Ubuntu Desktop 16.04

Problem Many (or all?) subdomains like files.slack.com and guide.elm-lang.org get DNS_PROBE_FINISHED_NXDOMAIN on Chrome. Using nslookup returns: Server: 127.0.1.1 Address: 127.0.1.1#53 ** ...
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0answers
25 views

How can I use iptables to duplicate outgoing DNS requests and send the copy to a different nameserver?

I have a host running Debian which is making DNS requests to some nameserver. My goal is to copy the outgoing DNS requests, change the destination IP and fire away. The authoritative copy is still the ...
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0answers
7 views

Issue in network routing when load balancing a network system

Trying to Bypass a load Balancer Our system directs network traffic across a three way load balancer serving three cellular modems in normal operation. We use a program called speedtest_cli that ...
2
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0answers
36 views

socat parent process killed by failed connection

Short Question Failed connection attemps to a forking socat process seem to be killing the parent process. Is this a bug? What's the best solution to this? Long Question I'm running a socat server (...
0
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1answer
34 views

linux & identify the interface name on remote machine

lets say I want to ping to some machine as from my machine - moon ping -c 1 master01 now I want to understand what is the interface name in master01 machine that get the packet from ping so how we ...
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0answers
10 views

Using an external WWAN modem instead of the inbuilt one

I have a Dell Latitude 7280 on which I'm trying to install Linux. One problem is that I've only mobile broadband. ATM I'm trying to install NixOS but it's unclear if I'll keep it (haven't tried it yet)...
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1answer
32 views

How to find out the interface which is being used for internet?

I have multiple network interfaces and I am not sure which interface is being used for the internet connection. I tried the methods which are listed in the question How to find out which interface ...
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1answer
34 views

What are the differences between qperf and ping test latency results?

I am wondering what are the differences between qperf and ping tests latency results. In terms of measuring latency between two servers which tool result could be considered more accurate? ping: ...
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2answers
29 views

Telnet to a closed port does not reply connnection refused

I have a server with a docker and a UFW firewall (I know it might have conflit because docker open some port despite UFW rules) but: When I telnet this server from outside on a random closed port, ...
0
votes
1answer
21 views

nc getting stuck unexpectedly

I expected this: nc -l localhost 7000 </dev/null & nc localhost 7000 </etc/profile and this nc -l localhost 7000 </etc/profile & nc localhost 7000 </dev/null to finish after ...
0
votes
1answer
19 views

config ip adrress of a network interface through ubuntu terminal [duplicate]

I am trying to configure ip address of network interfaces through terminal in ubuntu systems. So far successfully changed the IP address and other things through editing the interface file in the ...
1
vote
1answer
40 views

Why would properly VLAN tagged multicast traffic not arrive on the tagged interface?

I'm working with an application that sends multicast traffic between a client and server. This traffic is sent via multicast. The client and server are both using VLAN interfaces, and need to ...
5
votes
1answer
69 views

Shutting down interfaces takes a very long time

I have ran into a most annoying problem when rebooting/ shutting down. For some odd reason the shutdown always takes the "maximum" amount of time. I have been able to trace the cause to be ...
1
vote
1answer
57 views

Virtual NICs in Ubuntu 18.04

We are a group of students completing a development project unit at the University of Sydney. We have had difficulty with linux routing, and would really appreciate being pointed in the right ...
1
vote
1answer
20 views

How to specify a route among three interfaces in a router

I have this setup: 10.5.128.150 Ubuntu Ubuntu eth2 <------> server (10.5.128.154) client eth1 <----> eth1 ...
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0answers
32 views

multiple ipv6 from range on one machine

I have a debian server and a pool of ipv6 addresses with 64 mask. I want to split all ips between multiple servers, but configure it through masks, without adding 4 million ips to /etc/network/...
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3answers
73 views

Creating a simple FTP server

I'm a bit confused about the terminology for Linux FTP servers. I'm just attempting to set up a simple FTP server. I thought was accomplished by FTPd but there seems to be no client/server for FTPd. ...
1
vote
1answer
18 views

PulseAudio network stream not available on WiFi

I have PulseAudio streaming over my local Ethernet LAN. I play sound from my client (a laptop) to a PulseAudio "server" which is connected to speakers. Both run PulseAudio verion 12.2. When I switch ...
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0answers
22 views

I see my home's wifi, but I can not connect it in dual boot Kali Linux [duplicate]

I installed Kali Linux alongside Windows 10(dual boot). After that, I can't see any wifi connection.And, of course also I can't connect them. When I type this to command line : sudo iwlist wlan0 ...
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0answers
32 views

Dual Boot Kali Linux Cannot Scan Wifi Networks [duplicate]

Today, I have installed Kali Linux alongside Windows 10. After that, when I click wifi icon at the right top of the screen menu and again I click Select Network button, a screen show up but there is ...
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0answers
31 views

Locally Administered MAC addresses for WLAN ports in brctl

I am exploring Linux network stack by investigating outputs of various utilities on my home-grade router. My question is related to bridging. When I check the output of "brctl showmacs br0", it gives ...