Wired connection drops out randomly

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Wired connection drops out randomly

Post by Azvareth » Sun Aug 27, 2017 10:25 am

Wired connection drops out randomly, might be reenabled with systray icon "disconnect and reconnect"

First I am a "lamer" when it comes to linux so please excuse me beforhand if I use bad terminology.

Ever since I did the last update of Linux mint I have experience various internet connection problems, I did a websearch and found out that it might depend on a "systemd-dns" thing, I followed the instructions at this site "http://www.hecticgeek.com/2017/04/ubunt ... ns-issues/" and did a change to "unbound"

However I am now faced with randomly "internet" connection dropouts, first I solved it by rebooting Linux to regain connection, later on I discovered that I could use the systray connection icon to close and reopen the connection to get it to work until next randomly dropout...

I have searched the web (and this forum) but it is quite hard to find a similar experience as mine.

As a sidenote, my main machine experienced the same initial thing, however the only thing I did on that machine was to disable the DNSSEC and as far as I can tell it is working for now, even if it may not be as secure.

So my question is, does anyone know how to fix it or what may be wrong with this setup? As far as I can tell, Win10x64 do not drop internet connection (but lacks drivers for graphics card = bad youtube)

HW Information:

Linux Mint x64 18.2 and all updates to this date.
CPU: AMD Athlon(tm) 64 Processor 3200+ (2GHz) single core
Mem: 4x512MB DDR 400MHz
Eth: 88E8053 PCI-E Gigabit Ethernet Controller, Marvell Technology Group Ltd.
Gfx: GeForce 8500 GT

no wireless, one satadrive (FUJITSU MHY2160B) shared with a Windows 10x64 installation.

usage is for youtube, shoutcast and webbrowsing.

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Re: Wired connection drops out randomly

Post by manselton » Sun Oct 22, 2017 9:51 am


Did you ever get to the bottom of this? I've just installed Sonya and I'm getting similar troubles. However, reading your post and link I realize I've not altered systemd nor the network manager. So I'll have to look into that. I'm a big fan of Unbound and OpenBSD has just incorporated it into its core system. - Very big kudos regarding its security and simplicity.

I believe the project leader is Wouter Wijngaards and he has 5 days ago put and example unbound.conf here:
https://github.com/jedisct1/unbound/blo ... le.conf.in It makes interesting reading if you like the nitty gritty but it is far more complex that needed for a desktop.

Unbound can be used for ad-blocking too. And I'm not seeing messages complaining of me blocking these ads neither! 70% of ads come from 7 servers. Added these lines to the server section. An OpenBSD dev reckons it is better that using the /etc/hosts file to block sites.

local-zone: "doubleclick.net" redirect
local-data: "doubleclick.net A"
local-zone: "googlesyndication.com" redirect
local-data: "googlesyndication.com A"
local-zone: "googleadservices.com" redirect
local-data: "googleadservices.com A"
local-zone: "google-analytics.com" redirect
local-data: "google-analytics.com A"
local-zone: "ads.youtube.com" redirect
local-data: "ads.youtube.com A"
local-zone: "adserver.yahoo.com" redirect
local-data: "adserver.yahoo.com A"
local-zone: "ask.com" redirect
local-data: "ask.com A"

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Re: Wired connection drops out randomly

Post by manselton » Tue Oct 24, 2017 11:37 am

So far as I can understand, the link Azvareth gave to HecticGeek's blog http://www.hecticgeek.com/2017/04/ubunt ... ns-issues/ does most of the digging for understanding. The discussion comments are especially good. Disabling resolvedconf did not seem to do much for me. As I see it the need was to disable dnsmasq or else unbound and dnsmasq are both trying to do the same job! Dnsmasq gets put aside by pre-pending nameservers for unbound: I put these in /etc/resolvconf/resolv.conf.d/head

nameserver # unbound dns server on my local machine
nameserver # one of the opendns servers
nameserver # google's primary dns server

exactly the same thing can be achieved with a prepend statement in /etc/dhcp/dhclient.conf . Here is the output of

$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)



(If a dns query in not in unbound's cache it gets handed off to opendns and then unbound captures it. ) The second stanza was previously including (the home-router) and/or 10.9.??.?? (my ISP's dns server). These both mean that my ISP could track me through dns.

Two things annoyed me during the investigations. Systemctl gave no error message on "# systemctl restart unbound" (I've not run a Linux system for 6 or 7 years so I don't know systemctl at all.) And, secondly, all attempts to insert a file /etc/unbound/unbound.conf to override the defaults resulted in unbound failing to start. The only way around this was to add files containing modifications to the directory and /etc/unbound/unbound.conf.d/ and put include lines only into /etc/unbound/unbound.conf e.g.

include: /etc/unbound/unbound.conf.d/unbound.adblock.conf
include: /etc/unbound/unbound.conf.d/noremote.conf

The default install has remote keys for distant admin but I don't need or want that. noremote.conf simply includes this

control-enable: no

Lastly my vpn was giving me trouble. Privatetunnel.com - run by the folk who write openvpn. They told me to put 3 lines into my .ovpn file :

scrlpt security 2 ## This allows the calling of inbuilt and user scripts.
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf

to run the inbuilt update resolve scripts.

Hope this helps someone.

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