[Solved] network-manager : DNS management broken after last upgrade
Tofloor
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th3blad3runn3r
deepin
2017-09-11 04:46
Author
Edited by th3blad3runn3r at 2017-9-12 08:46

Since last upgrade (1.8.2), network-manager package seems to have a huge issue, preventing correct DNS resolution (either via dhcp or static address)

All outgoing requests fail with either a
  • Temporary failure in name resolution
  • Err_name_resolution_failed

I tried several things, without luck to fix it
Declaring a nameserver in /etc/resolv.conf does the trick as long as it is not overwritten by NetworkManager (reboot or interface restart)
For example, altering /etc/resolv.conf this way, will help you... for a while
  1. # Generated by NetworkManager
  2. nameserver 127.0.0.1
  3. nameserver 8.8.8.8
Copy the Code

So far, I suspect network-manager-l2tp to be the root cause.

Anyone else stuck with this problem ?

Thanks in advance



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mightymak
deepin
2017-09-11 14:29
#1
I'll have the same problem and could not find a solution besides the temporary fix provided by th3blad3runn3r.

@th3blad3runn3r: Thx for the hint.

@deepin: Any clues?
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yanbowen
deepin
2017-09-11 17:45
#2
Please edit the file '/etc/NetworkManager/NetworkManager.conf', comment the line 'dns=dnsmasq', then reboot.
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th3blad3runn3r
deepin
2017-09-11 22:59
#3
https://bbs.deepin.org/post/145344
Please edit the file '/etc/NetworkManager/NetworkManager.conf', comment the line 'dns=dnsmasq', then ...

Thanks @yanbowen.
I will test this tonight.

A far as I understand, this seems an issue related to DNS caching.
Do you believe that dnsmaq is the real culprit ?
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yanbowen
deepin
2017-09-11 23:46
#4
https://bbs.deepin.org/post/145344
Thanks @yanbowen.
I will test this tonight.

This is just a guess, but it's a big possibility, because the update adds this line of configuration.
In addition, according to user feedback, the problem is solved after modification.

By the way: have you ever defined DNS Settings?
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th3blad3runn3r
deepin
2017-09-12 01:44
#5
Edited by th3blad3runn3r at 2017-9-11 10:47
https://bbs.deepin.org/post/145344
This is just a guess, but it's a big possibility, because the update adds this line of configurati ...

By the way: have you ever defined DNS Settings?
Nope. I used to, a few months ago, but for now, I'm relying on my gateway settings.

I'm not in front of my box to ensure that dnsmaq is running, but if so, disabling it, will IMHO affect (slightly, for sure), DNS resolution perfs.
Anyway, thanks a lot for the tip, i'll let you know if the workaround does the trick

Thanks again
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th3blad3runn3r
deepin
2017-09-12 07:55
#6
https://bbs.deepin.org/post/145344
This is just a guess, but it's a big possibility, because the update adds this line of configurati ...

https://bbs.deepin.org/user/33250 :
You made my day, dude !

The workaround is working in either way :

  • Remove dns=dnsmasq form NetworkManager.conf
        OR
  • sudo apt-get install dnsmasq to add caching, which is not enabled by default, and cause DNS resolution to hang


Both are working solutions and fix the problem.



HUGE thank you !

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mightymak
deepin
2017-09-12 10:56
#7
Thx guys! Working at all!
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yanbowen
deepin
2017-09-12 17:32
#8
....
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