I am running openSUSE Leap 15.1 (Yes, it is alpha)

My router (FritzBox 7390) says everything is okay.
I am connected to DSL switch 177.238
and the name servers 217.237.150.51 and 217.237.148.22 respond to ping.

But I cannot connect to any webpage, except 192.168.178.1

For example:
ping formal.iti.kit.edu
yields
temporary error in name resolution

but
ping 141.3.26.2
succeeds with
64 bytes from 141.3.26.2: icmp_seq=1 ttl=51 time=14.3 ms

But entering this IP in the firefox browser results in

page not found

What can I do?
Any help highly appreciated.

Peter

Looks like a nameserver configuration issue to me.

Did you try google's public dns for a start ?

# echo 'nameserver 8.8.8.8' > /etc/resolv.conf

and then try

# ping google.com

followed by your browing your site ? Also check your firewall in case it blocks things .

# iptables -nvL

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Try to query the name servers directly.

dig @217.237.150.51 google.com

If that doesn't work, ensure you can resolve from any name server.

dig @8.8.8.8 google.com
and/or
dig @1.1.1.1 google.com

If you cannot resolve any of these, maybe there is a firewall blocking traffic somewhere?

1 members found this post helpful.

Note that will wipe out your existing /etc/resolv.conf

Instead, please post the contents of /etc/resolv.conf, using [code] tags.

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Thanks pingu_penguin, thanks savona,

the file /etc/resolv.config now contains just one line

nameserver 8.8.8.8

and everything I tried so far works.
(with the exception that fritz.box could not be resolved.
But I can live with that)

The dig command also works, but I tried it after
adding the above line to /etc/resolv.config

Peter

You should add a second IP to the etc resolv file. Use Google: 8.8.4.4

Should I also add the original nameservers 217.237.150.51 and/or 217.237.148.22?

That is up to you. There is nothing wrong with using googles, or cloudflare.

As I had said above the advice so far received from this forum solved my
original problem at home.
But it did not work when I tried to connect to the internet at an institution,
that allows me to use their computing infrastructure. With further advice I have
now arrived at the right solution. I want to share four observations with you

(1) host name resolution works vastly different for different Linux distributions, so
only information pertaining to openSUSE was relevant in my case

(2) do not change /etc/resolv.conf manually, it is an automatically generated file

(3) there seems to be more than one way to configure host name resolution. On my computer
"networkmanager" takes precedence over yast. So I used nmcli (network manager command line interface)
to configure host name resolution. nmcli has very comprehensive and well organized
help features, so you will sure find the proper command you need. Start with nmcli --help.

(4) I my case I had to set "ipv4.dns-search" to the correct list of hosts. At home I use "fritz.box"
at the institution the host their system administrator told me.

Hope this my be useful for people with similar problem.

wirelessly, i suppose? different situation.
but not the solution?
i respectfully disagree.
there are differences, but that involves the softwares used, not the distros themselves.
softwares - mostly it comes down to:
- systemd or something else
- networkmanager or something else

not necessarily.
i have a (self-written) script that changes resolv.conf daily, and nothing interferes.
but i think i had to uninstall one software that essentially did what my script does now.

+1 for nmcli.
but isn't "yast" a package manager? i don't see how that can take precedence over network managing software.
what, where? in /etc/resolv.conf? is that the "solution" to the problem? i don't think you fully explained it.
does it now work satisfactorily in both places without having to switch configurations?

and i hope my additions may be useful for people with similar problems.

1 members found this post helpful.

I largely agree with ondoho's comments. However, just to clarify that "YaST" actually consists of a suite of configuration modules (of which one module represents the GUI software management utility).
https://en.wikipedia.org/wiki/YaST

@pschmitt: Nonsense. YaST is used for network management when using wicked (essentially the traditional ifup/ifdown framework commonly employed for server configuration in static network environments). Network Manager is designed for user-control in mobile/dynamic network environments (eg laptops moving between home, study, and work environments). One should understand which network management framework is active, before trying to resolve the network configuration issue at hand. Only one system should be active at a given time.

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There is hardly any post that could not be improved.
Thanks ondoho for commenting on mine.
I am sure your contributions will find a thankful audience.
Further comments and additions follow:
I do not know why from some point on the QUOTE
mechanism stopped working.

Yes, the post concerns wired connections only.
Correct. I only gave a pointer to the solution.
You have a valid point here. As an unsophisticated user I usually stick with
the default settings. So, on my Ubuntu machine I have to deal with systemd and on
my openSUSE machine it's the networkmanager.
I should have written:
Do not change /etc/resolv.conf manually unless you know exactly what you are doing.
The first thing I did when the problem first materialized, I started yast and selected in the system section
network settings. After a short while I got the waring:
The network is at the moment controlled by NetworkManager or completely deactivated
(Das Netzwerk wird im Moment vom NetworkManager gesteuert oder ist komplett deaktiviert.)

[QUOTE=ondoho;5980965]
what, where? in /etc/resolv.conf? is that the "solution" to the problem? i don't think you fully explained it.
/QUOTE]
Let me give some more pointers. You start with
nmcli --help
Looking at the OBJECTS section you see that "connections" or "devices" sound promissing.
After
nmcli c help and nmcli d help
You realize that it is connections that you want to explore further.
nmcli c show
gives you information on the current situation.
With

nmcli edit

you start an interactive editing process. At this point you will probably have to enter your
superuser password.
At every point in interactive editing you can enter "help" . This way you discover that you need:

nmcli connection edit ethernet

You again get a list of possible continuation from which I selected

goto ipv4

Again you see a list of possible properties you can change. I selected

dns-search

Then entered the desired value for this property.
After having done this it is important to go back up one level
and select among the possible command

save persistent

[QUOTE=ondoho;5980965]
does it now work satisfactorily in both places without having to switch configurations?
/QUOTE]
For all I can say after 2 days it works perfectly. No switch of configurations needed.
The value of dns-search is a list. My guess is, that the system checks which host in the
list is available and sticks with the first one.

Thank ferrari for your clarification.
I agree with everything you said.
I should not have used the phrase "takes precedence over"
but maybe "network manager is active"