Linux networking issue Q.

[Jethro_uk]

Upgraded to Linux Mint 19 ("Tara") a few days ago, after running it off a live CD to check compatibility - and it ran fine.

Am now getting sporadic irritating DNS errors when browsing (Chrome). Generally DNS_PROBE_FINISHED_BAD_CONFIG. Reloading the page seems to work, although sometimes it takes two or three goes.

Have swapped DNS servers in my network config, but it doesn't seem to make a difference.

Running a DNS client text

doesn't give any clues.

So what's changed, and (more importantly) how do I fix it ?

SWMBO iPad (which uses router default Google DNS server settings) seems unaffected. As is my smartphone and tablet (both Android). So I'm pretty confident it's something inside Linux that has *become* borked.

(Also the appearance of PAN and Thunderbird have changed. They now look "washed out".)

[Theo]

It seems that error means your DNS is broken, but it's unclear why. It could be a more general network problem

Have you tried using Google Public DNS: 8.8.8.8 and 8.8.4.4 as DNS servers, instead of those providers by your router/ISP, which can be unreliable.

might be relevant. (I'd try the second answer before the first one) But I suspect the error could be one of a number of things, and the above only addresses one of them.

Are you using wifi or wired ethernet? If wifi, what type of adaptor? Have you tried another browser like Firefox? Does Thunderbird etc connect reliably?

Theo

[The Natural Philosopher]

Um.

Start by totally disabling IPV6.

I had some shitty issues with DNS and I isntsalled something other than DNS masquerade app, In fact I think I intsalled full BIND because ut insisted on using the router as a DNS server.

This may be a fix

Essentially if the link between /etc/resolv.cong and what its supposed to link to is broken, you may need to remake it

That may be something you can fix in the display section by reducing the gamma.

Now on my system that means using the 'nvidia X server' thingy in control centre.

YMMV on that depending on your video hardware

[Cursitor Doom]

Is Chrome open source? I don't trust anything tied in with G****e.

[Theo]

[Adrian Caspersz]

Technicolor router by any chance? Old firmware?

You probably have the setting 'WANDownSpoofing' still enabled, and the router is now caching duff DNS info. Easy to disable, if afflicted.

[Jethro_uk]

Thanks for all the replies, guys.

Current status is having fired up nmcli to start chasing things down, I noticed that the DNS settings for my interface were wrong. They were still set to googledns (8.8.8.8) even though I had set them to be OpenDNS as part of testing - but that was via the GUI applet.

An ifconfig eth0 down/ifconfig eth0 up caused the changes to be picked up and currently it's been 8 hours surfing with no errors.

Not sure what was wrong with googles DNS, or if there was some arcane caching issue that resetting the adapter flushed out. But as long as its working.

If I could be bothered, I'd play around a see if there is a bug with the GUI that doesn't save changes.

Generally Mint 19 seems great. Two other niggles are something weird has happened to the display: Thunderbird and Pan now looked "washed out" ????? Also the current version of Pan is broken - I had to go back and install the older version that ships with Xenial.

[Brian Gaff]

I don't see how it can be anything to do with the server as he already said other hardware still works fine.

Brian

[Brian Gaff]

That has been reported elsewhere. Pan sometimes will not get message bodies apparently thinking it has. Brian

[Andy Burns]

Different GNOME theme installed?

[Jethro_uk]

Well, if it was, it was done behind my back ...

[Jethro_uk]

And the winner is .... :)

Not GNOME theme, but Mint Theme ...

For reasons best known to themselves (why do they do that ????) the MINT team went from "Mint X" to "Mint Y" theme for buttons. But that also affects the text in PAN and Thunderbirds main windows.

Back to how I liked it now, thank you sir !!!!

[Theo]

Each of them are using different DHCP implementations, so it's still possible for a conflict with the server end. If some are doing IPv6 and some aren't, even more so.

Theo