Questions tagged [networking]

Managing and using network connectivity on a Ubuntu system

9,091 questions with no upvoted or accepted answers
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Ubuntu 18.04.2 LTS server - network configuration problem during setup

Has anyone had the same problem? When installing from current server iso's in a VMWare VM and without a DHCP Server present, both Ubuntu installers are not able to manualy configure a ethernet ...
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860 views

Can't access GitHub via Google Chrome?

I successfully run the command ping github.com. Output is like: PING github.com (192.30.253.112) 56(84) bytes of data. 64 bytes from lb-192-30-253-112-iad.github.com (192.30.253.112): icmp_seq=1 ttl=...
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SSH - UsePAM yes or no?

After setting up SSH key-based authentication, people are advised to disable SSH password authentication. This is done by navigating to /etc/ssh/sshd_config and making sure that the following line is ...
7
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1answer
11k views

dnsmasq : failed to create listening socket for port 53: Address already in use

I'm trying to configure dnsmasq to work along with NetworkManager, the problem is when I try to run the service it fails with: dnsmasq: failed to create listening socket for port 53: Address already ...
7
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1answer
9k views

What are the use cases for cloud-init?

Installing Ubuntu Server 18.04, I see the networking config in /etc/netplan has a .yml file that talks about CloudInit and networking configuration not persisting across instances. I have read https:/...
7
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1answer
288 views

How do I remove the long name given to my internet connection?

The other day my computer randomly started displaying the full name of my ethernet controller as you can see here: I'm fine with it saying Ethernet Controller like it used to but having the whole ...
7
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3answers
387 views

Wifi connected but Internet drops frequently

I spent more than 2 weeks searching for a solution to the following problem without success: On my Ubuntu 18.04, I am connected to a Wifi (named "SmartCampus") but the internet keeps dropping ...
6
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0answers
327 views

USB Ethernet + thunderbolt errors

Currently having major issues with thunderbolt ethernet adapter. The device is a "Razer Core X" thunderbolt eGPU enclosure which has a built in USB3 hub and gigabit ethernet port. Essentially a very ...
6
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0answers
234 views

NetHogs showing suspicious (outgoing) traffic to random ports from root on Ubuntu 16.04

Using NetHogs on an Ubuntu 16.04 (web) server, i.e. on a machine where no consumer applications or web browsers are installed, besides traffic that is to be expected (HTTP and SSH) PID USER ...
6
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1answer
276 views

Torque: Unauthorized Request

Following this guide: https://jabriffa.wordpress.com/2015/02/11/installing-torquepbs-job-scheduler-on-ubuntu-14-04-lts/ I installed TORQUE on Ubuntu 16-04-lts (he claims the process works the same ...
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0answers
2k views

How to reset netplan to default in 18.04?

I tried creating a network bridge through Virtual Machine Manager for KVM. Now my Ubuntu network connection depends on my Windows KVM being booted. Since creating this bridge when Ubuntu is booted ...
6
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1answer
15k views

16.04 - curl: (35) gnutls_handshake() failed: Error in the pull function

When trying to connect to a HTTPS websites, I get this error curl: (35) gnutls_handshake() failed: Error in the pull function.. In detail: curl -vvv "https://example.tld" * Rebuilt URL to: https://...
6
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2answers
401 views

Is there a way to prevent USB over ethernet from working?

This video shows an attack where attaching a USB device to a locked computer pretty much takes over all currently running browsers. The trick is that the USB device acts as Ethernet over USB, and a ...
6
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0answers
629 views

Cannot Get Xdmx to work with two Ubuntu Computers (xinit error)

I have two computers running Ubuntu 16.04 with Unity, and I'd really like to use the distributed multihead (Xdmx) software in order to use one of the computers as a second monitor, instead of just ...
6
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0answers
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Problem with PBISOpen and Ubuntu 14.04LTS

I'm testing openpbis 8.3 version and I have authentication problem when I'm trying to open new session on Ubuntu 14.04 LTS, not in local network but only in distant network. Adding the computer on ...
6
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1answer
748 views

(32) Ad-Hoc mode is not supported by this device. - 13.10 on i5 NUC

Not sure if this is an Ubuntu issue or intel issue. Any insights will be appreciated. I have an intel NUC (D54250WYK) w/ intel 7260 wireless adapter and Ubuntu 13.10. I can connect to my local wi-...
6
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2answers
8k views

Can't control connection bit rate using iwconfig with Atheros TL-WN821N (AR7010)

I'm trying to reduce the connection bit rate on my Atheros TP-Link TL-WN821N v3 usb wifi adapter due to frequent instability issues (reported connection speed goes down to 1Mb/s and I have to ...
6
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0answers
859 views

How can I connect to Microsoft Direct Access?

My company has moved from Cisco VPN to Microsoft Direct Access. I was using network-manager-vpnc to connect from Ubuntu before. Can I use the same to connect to direct access? If not, how can I ...
6
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1answer
4k views

How to disconnect internet when VPN fails?

Normally I'm connected to the Internet with a VPN, but sometimes it fails and some programs may automatically start to use the default unsecure connection. How do I disconnect all the internet until ...
5
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1answer
160 views

Sysctl IPv6 disable autoconfig for all interfaces not working

I am trying to turn off IPv6 autoconfig for my all interfaces (I have 4). I want to use net.ipv6.conf.all.autoconf = 0 In the my sysctl config (under /etc/sysct.d) But the settings not applied for ...
5
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1answer
4k views

Setting up barrier to run on startup

Barrier is a free popular KVM software that enables mouse/keyboard sharing across several devices. I've been fiddling with it for a few hours and I can't seem to get it right. I have a barrier ...
5
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1answer
1k views

WiFi randomly (or under load) disconnects on Ubuntu 18.04 with Qualcomm Atheros QCA6174

With reference to this topic: I have changed WiFi powersave to off. IPv6 support disabled. I have reinstalled Linux firmware. But nothing helped. The network still disconnects at random times [EDIT]...
5
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1answer
232 views

Openvpn connection problem using network manager

I have problem with connecting to vpn my company gave me those files along with a password I tried to import them this way 1- I go to Network Setting 2- then I press the plus button to add new ...
5
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0answers
766 views

A stop job is running for Raise network interfaces (/1min 31s)

When I am trying to shutdown my pc running ubuntu 16.04.5 it will hang on this line: A stop job is running for Raise network interfaces (1s/1min 31s) This is my /etc/network/interfaces file: # This ...
5
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0answers
5k views

Cisco AnyConnect: Posture Assessment Failed: CSD library signature verification failed

All of a sudden AnyConnect stopped working. Version 4.5 on ubuntu 16.04. I'm now getting the following error when trying to connect. Any ideas on how to resolve it?
5
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0answers
176 views

How to automatically switch default printers based on your location

I wonder if is it possible to automatically switch the default printer according to the wifi network to which the computer is connected. Apparently, windows has this feature
5
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1answer
2k views

Opening a port to an application accessible outside of localhost?

Though I have researched this all day, I still can not find a solution to this issue. On my Ubuntu Server I am trying to run a node.js application that simply prints out "Hello World" and runs on ...
5
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0answers
5k views

wpa_supplicant[949]: wlan0: Failed to initiate sched scan

I installed ubuntu 14.04 lts with gnome, I connect normally to wifi of my house, but in my college i can't, my colleges wifi is an open wifi with a html login page. My notebook is a dell Inspiron 14. ...
5
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1answer
3k views

Apply static IP address change in /etc/network/interfaces in Ubuntu 16.04

TL;DR: In Ubuntu 14.04, If you change a static IP address in /etc/network/interfaces and apply the changes with ifdown and then ifup command everything works fine. But this sequence is not working in ...
5
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1answer
1k views

Freeze on losing network connection

When I mount a server file system that is located in a local network over nfs on my laptop, the processes interacting with the filesystem freeze / hang up whenever the network connection is lost. The ...
5
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0answers
2k views

Wifi keeps disconnecting on HP 2000-2c10DX

My wifi keeps dropping connection constantly. I really want to use Ubuntu as a main OS, but this wifi problem is an issue. In the past, upgrading the kernel fixed it, but it isn't fixing the problem ...
5
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0answers
2k views

cat: /var/lib/misc/dnsmasq.leases: No such file or directory

I've searched all over the internet, but couldn't find any answers of my problem.. I want to connect my Raspberry Pi to my laptop. But whenever i try to check the ip address of my raspberry, i get ...
5
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0answers
8k views

How to see log of nmcli “Network connection failed :unknown reason”

My country has network block, so when i use "nmcli connection up uuid", it always show "connection establish successful" and then show "Network connection failed :unknown reason:" right now, I find ...
5
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0answers
1k views

How do I force nmcli to reconnect to different uuid?

I have a bash script that checks my network environment and mounts shares accordingly. If I'm at work and have a hard-wire connection to the LAN, then I'd like to activate a hotspot connection for ...
5
votes
1answer
19k views

Getting WiFi AP working with hostapd and isc-dhcp-server [Xubuntu 14.04]

I have tried using ap-hotspot from WebUpd8, and it did not work for me in 13.10 or 14.04, so I have been working on getting hostapd manually set up, using isc-dhcp-server since dnsmasq was having ...
5
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1answer
2k views

Cannot change Wifi settings, stuck on WEP Security

I just started using Linux and as such do not have a proper knowledge of how to use the command line and all of those sorts of things, so please try to bear with me :). I have been able to connect to ...
5
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1answer
10k views

Openswan's ipsec verify fails on “Two or more interfaces found, checking IP forwarding”

I'm trying to set an L2TP/IPsec VPN. I have installed openswan from the repository on Ubuntu 13.04 Section: universe/net Architecture: amd64 Version: 1:2.6.38-1 and configured it following the ...
5
votes
1answer
5k views

Connected to wireless, but no internet access

After installing Ubuntu 12.04 a week ago wireless internet had been working fine. It stopped working yesterday, however, and I'm at a loss for what to do even after scouring replies to similar posted ...
5
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2answers
5k views

Wireless not connecting automatically

My wireless is working fine, but when I login, it does not connect automatically, I have to select it from the list each and every time to use it. Even though the connect automatically option is ...
5
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0answers
5k views

Playing Age of Empires II multiplayer in VirtualBox Over wi fi network

I installed Age of Empires II (Expansion) in VirtualBox (hosting Windows XP). It works great in single player mode. Unfortunately, I tried playing multiplayer via WI-FI which I created on my Ubuntu ...
5
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1answer
12k views

Bluetooth adapter not found in Ubuntu 16.04

Since my upgrade to 16.04 the OS does not find the bluetooth-adapter anymore. The Laptop is an Acer Aspire V5-573G and all i can find about the bluetooth adapter is this: "Bluetooth Qualcomm Atheros ...
4
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3answers
172 views

How to make Windows guest running on qemu/kvm obtain IP address from physical router with DHCP server?

I am running Windows XP as a guest on Ubuntu 18.04 LTS with qemu/kvm. I want to use this Windows instance to manage my CCTV IP camera which uses ActiveX applets. I need this Windows XP to get IP from ...
4
votes
1answer
397 views

Qualcomm QCA6174 - Wifi Unstable - Dell XPS 13 9380 - Ubuntu 20.04 Focal

I have Ubuntu 20.04 installed on Dell XPS 13 9380 (Service Tag: 8SGZPV2) with Qualcomm QCA6174 wifi chip. Every 2-5 minutes, the wifi signal drops off then comes back online after a few seconds. This ...
4
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0answers
48 views

A strange path is being printed for an entry when netstat command is used?

When I used the netstat -a command to check for active connections, I encountered this entry under active unix domains sockets(servers and established) Proto Refcnt Flags Type State ...
4
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0answers
761 views

Ubuntu 20.04 LTS - Detecting 5GHz wifi takes long time

I have two hidden wifi networks in range of my laptop (2.4 GHz and 5 GHz); immediately after a boot, I see only the 2.4 GHz network; the 5 GHz becomes visible only after a minute or two. After this ...
4
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2answers
159 views

IP command using to 100% CPU on wakeup

On laptop wakeup I see a process called ip that uses 100% CPU. It won't stop on its own, I need to manually kill it every time. By looking for it in ps I could find that the command being run is ip ...
4
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0answers
335 views

19.10 dhclient + resolvconf not updating resolv.conf

I am not running systemd.resolved, not do I wish to. Am am using netplan, systemd.networkd, resolvconf, dhclient /etc/resolv.conf is a link -> ../run/resolvconf/resolv.conf The resolvconf hook from ...
4
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0answers
1k views

Trying to route traffic through a tunnel server error: “Nexthop has invalid gateway”

Short version: we have servers in another data center and we have an openvpn tunnel between them. For the first time, I need to hang server on a different subnet from the tunnel server and I'm ...
4
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2answers
4k views

What does mean DORMANT mode in ip link show wlan0?

As the title above, does anyone know what DORMANT mean in this output command ? $ ip link show wlan0 3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DORMANT group ...
4
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1answer
1k views

Bridging LAN and WIFI using netplan not working and killing AP

I'm trying to extend my local LAN network via WiFi and would like all devices in the same network. The setup is as follows: DHCP/DNS server running inside the LAN separate PC linked to the LAN, with ...

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