All of a sudden none of my browsers on my netbook will connect to any address. Not even an IP. Skype connects normally, and I can ping IP addresses but not web pages. It reports “ping : unknown host www.google.com”. I haven’t been fooling around with YaST, but I suspect I have accidentally blocked a port. I use Network Manager it and reports that I am connected both with wire and wireless connections.
Nobody can ping web pages. A system can (try to) ping another system. And pinging is not influenced by the availablity of a listening port for any other service (like 80 for HTTP).
But when, using whatever going over the net program, it says “unknown host”, there is a problem with name resolving. In other words, you gave it a host/domain name and it cannot be resolved to an IP address. DNS problem.
You can check name resolving with e.g.
henk@boven:~> host www.google.com
www.google.com has address 173.194.65.99
www.google.com has address 173.194.65.104
www.google.com has address 173.194.65.106
www.google.com has address 173.194.65.103
www.google.com has address 173.194.65.147
www.google.com has address 173.194.65.105
www.google.com has IPv6 address 2a00:1450:4013:c00::6a
henk@boven:~>
BTW why do you not post what you do by copy/paste from the terminal window between CODE tags here. Now we have to assume that your story telling is the truth and nothing but the truth and the complete truth, instead of that we can simply see and interprete what you saw :(.
So please show us the ping to an IP address that succeeded. And more that proves what you say.
All of a sudden none of my browsers on my netbook will connect to any address. Not even an IP. Skype connects normally, and I can ping IP addresses but not web pages.
You were a bit unclear as Henk mentioned. If you can ping an internet IP address successfully, then maybe it is just a DNS issue.
ion@linux-xzlw:~> ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
link/ether 00:22:15:6d:63:c1 brd ff:ff:ff:ff:ff:ff
3: wlp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:15:af:d2:97:50 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.65/24 brd 192.168.1.255 scope global wlp1s0
valid_lft forever preferred_lft forever
inet6 fe80::215:afff:fed2:9750/64 scope link
valid_lft forever preferred_lft forever
ion@linux-xzlw:~> ip route
default via 192.168.1.1 dev wlp1s0 proto static
192.168.1.0/24 dev wlp1s0 proto kernel scope link src 192.168.1.65 metric 9
ion@linux-xzlw:~>
I power-recycled the router. I also include a listing of my /etc/resolv.conf files…
My /etc/resolv.conf is blank.
My /etc/resolv.conf.OSPprb is blank
My /etc/resolv.conf.netconfig is search site
nameserver 192.168.1.1
My /etc/resolv.conf.Zna36Y is search site
Furthermore I booted from a backup openSUSE 13.1 SSD and was able to connect normally with no problems.
linux-xzlw:/home/ion # host www.google.com;; connection timed out; no servers could be reached
linux-xzlw:/home/ion #
ion@linux-xzlw:~> grep -i name /etc/resolv.conf
ion@linux-xzlw:~>
I am working under difficult conditions. I am presently in a rural community in Greece where my wireless Internet connection cuts in and out periodically. Not to mention that due to an electrical rain storm there have been power cuts. I have to walk to a nearby cafe to use their shared and slow computer. I do appreciate your assistance.
solved the problem. But the bigger question in my mind is how that could possibly have changed without any interference on my part. Admittedly it’s a small keyboard and I may have inadvertently pressed the “Fn” key but surely I should have received some kind of warning if that occurred.
Might be because of a crash or unclean shutdown, maybe even filesystem corruption.
Or some program overwrote it.
The thing is that netconfig doesn’t change the file any more when it was modified by something/somebody else (that’s why you had to specify the -f option, to force it to re-create the file). That’s by design, because it shouldn’t overwrite conscious changes made by the administrator.
I understand that you want to know the real cause. But as wolfi323 says, that is diifficult to find. In the past we had spme cases of changes to the file made (but not completely emptying it!), but if I remember correctly it was never nailed down to cause (but updates were accused).
In any case, as long as you do not work as root, destroying it yourself is by any means out of the question. That is as long as the permissions are correct:
henk@boven:~> ls -l /etc/resolv.conf
-rw-r--r-- 1 root root 887 17 jan 2014 /etc/resolv.conf
henk@boven:~
On 2014-09-27 14:46, hcvv wrote:
>
> I understand that you want to know the real cause. But as wolfi323 says,
> that is diifficult to find. In the past we had spme cases of changes to
> the file made (but not completely emptying it!), but if I remember
> correctly it was never nailed down to cause (but updates were accused).
If using automatic networking (ie, dhcp), it is possible that there is a
transient “misunderstanding” with the router, and the dns data is
cleared as a result.
–
Cheers / Saludos,
Carlos E. R.
(from 13.1 x86_64 “Bottle” at Telcontar)
A common cause if your machine mobile and moves from network to network.
My first reaction always is to try to re-acquire DNS by restarting the network
systemctl restart network
If that doesn’t work, then I sometimes specify a widely available DNS on the Internet instead of letting DHCP assign an ISP DNS.
A little off-topic but I see this also sometimes in virtualization, it’s just another layer of networking.