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User Help

How do I add an Internal Network adapter in VirtualBox without losing my NAT connection?

I have 2 VMs (A and B). I would like A, a Debian VM, to be able to access the internet and ping B. And, I would like B to be unable to access the internet but able to ping A. I have been using a NAT in the Adapter 1 slot for A alone […]

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Mastering Development System & Network

OpenVPN server on an Oracle Cloud computing instance: routing problems

I have an Ubuntu 20.04 LTS instance running in the Oracle Cloud "free tier". I set up OpenVPN on this VM following this guide (it’s in German). Firewall port 1194/UDP open, IPv4 forwarding configured correctly (both in /etc/sysctl.conf and in /etc/default/ufw, UFW also does forwarding in /etc/ufw/before.rules with this magic incantation: # START OPENVPN RULES […]

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User Help

What is the differences between the below 2 iptable rules?

I have a setup like below. RaspberryPI <==> OpenVPN Server <==> Internet <==> Client PC The RaspberryPI have an SSH server that is on a Dynamic IP. It is tunneled through the OpenVPN server so that the SSH server can be accessed via the OpenVPN Server’s Public IP. My question is, why Rule 1 allows […]

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Linux Mastering Development Ubuntu

Trouble with Ubuntu 18.04 netplan bridge

I’m stuck in here in the network configuration and I need help.. Plan is to create a KVM with windows running on a dedicatet ubuntu 18.04 server. So I need a networkbridge to reach the windows in my ubuntu. To try out this bridge-project I have create a ubuntu 18.04 server in my virtualbox and […]

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Linux Mastering Development Ubuntu

Diagnosing Ubuntu Ethernet Connection

I’m running Ubuntu 18.04.4 LTS, with Cinnamon as desktop environment. Yesterday my Ethernet connection disconnected and now I can no longer use the Internet; on Chromium the error is DNS_PROBE_FINISHED_NO_INTERNET. However, in my Network Manager, I am still connected to "Wired Connection 1". What steps do I take to diagnose where the problem is? Do […]

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Mastering Development System & Network

OpenVPN: Client cannot ping 4.2.2.2 when connected

My client cannot surf the internet when connected to the vpn. I have push "redirect-gateway def1" and root@vortex:/home# cat /proc/sys/net/ipv4/ip_forward 1 set. Sserver and client connect just fine and error free and can ping each other across the VPN, but that’s as far as it goes. root@vortex:/home# cat /etc/openvpn/server.conf mode server tls-server port 1194 proto […]

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Linux Mastering Development

CentOS 7: Slow wifi since some days ago

I’m using CentOS 7 and some days ago I started having slow wifi. These are some of my outputs (less than 1Mbps): uname -a Linux lhost.ldomain 3.10.0-1127.18.2.el7.x86_64 #1 SMP Sun Jul 26 15:27:06 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux ifconfig enp0s31f6: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 ether d4:81:d7:e8:0b:cc txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 […]

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Mastering Development System & Network

How to open port in client side in windows using my own pptp vpn server on linux?

I had been setup my own pptpd server in my vultr ubuntu server and i connect on it using my client built in in windows and i success to access the internet and when i check my ip i see the vps ip instead of my real ip, but my problem is when i try to open […]

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Linux Mastering Development

enp3s0 link DOWN after playing Quake Champions

Playing Quake Champions on steamplay. A few minutes into the game, my PC gets disconnected from my router. Things get back to normal a few minutes after, but sometimes I have to restart the PC. ip addr‘s output after I get the problem: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen […]

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Linux Mastering Development Ubuntu

enp3s0 link DOWN after playing Quake Champions

Playing Quake Champions on steamplay. A few minutes into the game, my pc gets disconnected from my router. Things get back to normal a few minutes after, but sometimes I have to restart my pc. ip addr’s output after I get the problem: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen […]