100% Packet Loss, But Network Up and DNS Fine

Desktop openSUSE 12.3 64-bit, updated almost daily.

When I fired up Firefox today, it couldn’t connect to Google (and the open internet in general). I checked my other devices and they reach the open internet fine.

Network Manager says connection speed to router on eth0 is 100 MBit/s, as usual.

ping google.com resolves Google to an IP address, but there’s 100% packet loss.

Using Firefox to connect to the router is fine. I can get to the router’s admin screens.

I haven’t changed any network settings in about a year…

Wired connection 1
X Connect automatically
X System connection

IPv4 Address Method: Automatic (DHCP), X IPv4 is required for this connection
IPv6 Address Method: Disabled, Privacy Extensions: Disabled, ] IPv6 is required for this connection
Ethernet Restrict To Interface eth0, X Autonegotiate
802.1x Security ] Use 802.1.x authentication

Did I update to something broken?

Thanks for the help!

Check routing table first. Sounds like it.

Check that a valid name server exists

grep -i nameserver /etc/resolv.conf
  • Your router may provide this service. If so, try rebooting it.

On Tue, 22 Apr 2014 09:06:02 +0000, arvidjaar wrote:

> Check routing table first. Sounds like it.

I would agree. Typically, DHCP-enabled routers provide DNS as well (at
least as a forwarder), so name resolution is likely local. Checking /etc/
resolv.conf would confirm that.

In which case, the routing table is the next place to look.

Jim


Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C

/etc/resolv.conf contains one entry, the router IP address:

nameserver 192.168.1.1


A router reboot resolved the problem, which is very puzzling to me. All my wi-fi devices (4 of them) were working fine. It was my hardwired desktop boxen that was hosed.

I’m using a Western Digital My Net N750. I guess periodic reboots are necessary.

Thanks all!

I’m glad it was as simple as that. :slight_smile:

On Wed, 23 Apr 2014 08:16:01 +0000, linuxvinh wrote:

> /etc/resolv.conf contains one entry, the router IP address:
>
> nameserver 192.168.1.1
>
> -----
>
> A router reboot resolved the problem, which is very puzzling to me. All
> my wi-fi devices (4 of them) were working fine. It was my hardwired
> desktop boxen that was hosed.
>
> I’m using a Western Digital My Net N750. I guess periodic reboots are
> necessary.

They shouldn’t be.

That the router is your name server explains why you were getting name
resolution when only able to connect to the local network. Everything
behaved as expected in that situation.

I have found that on occasion when I boot up connected to wireless and
wifi, if I disconnect one (I don’t remember which), if the one that’s
disconnected is the default route, sometimes the system will remove that
default route and not set the other interface to be the default.

Restarting network services (not the entire system) should be sufficient
to sort that out.

If it happens with just a single network interface, it would probably be
worth checking logs to see what happened. You could filter the logs on
the interface name (eth0 or whatever).

Jim


Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C

My desktop boxen is only hardwired - no wireless at all. The sequence of events:

  1. powered up desktop boxen

  2. launched firefox

  3. mail.google.com

  4. browser hung

  5. checked twitter on phone to see if ISP made any service disruption announcements

  6. noticed that phone was connected to wi-fi and using it

  7. picked up wi-fi only tablet and went to google.com, no problem

  8. checked cable connections

  9. noticed that boxen connection to router was fine

  10. logged into router, worked

  11. starting pinging 8.8.8.8 and google.com, 100% packet loss, google.com resolved to a proper IP address

  12. restarted the boxen a few times but no change in pings

  13. broke out the netbook and posted here

  14. next day, powered up boxen

  15. problem still persisted

  16. rebooted the router

  17. everthing back in order

Wouldn’t the network services be restarted on the boxen restarts? Or is there a persistent state that gets saved?

The router is configured to lease a connection to each device for six days at a time. I’m wondering if something went wrong and the particular leased connection from the boxen to the router stayed hosed until the router could be reset and “cleaned”?

I’ll look through the logs tonight…

On Wed, 23 Apr 2014 21:56:01 +0000, linuxvinh wrote:

> Wouldn’t the network services be restarted on the boxen restarts? Or is
> there a persistent state that gets saved?

If you do a powerdown/powerup (actually a suspend/resume should as well),
then yes, the service woudl be restarted.

> The router is configured to lease a connection to each device for six
> days at a time. I’m wondering if something went wrong and the
> particular leased connection from the boxen to the router stayed hosed
> until the router could be reset and “cleaned”?
>
> I’ll look through the logs tonight…

If a router reboot resolved it, then it is likely something with the
router. I have seen the odd thing like that, but you might also check
your router logs if it maintains them across a reboot.

Jim


Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C

The router log is gone.

I’m not sure what I should be looking for as it pertains to the desktop logs. It would probably be easier to find in real-time should the problem happen again.

Thanks!

On Thu, 24 Apr 2014 07:06:01 +0000, linuxvinh wrote:

> I’m not sure what I should be looking for as it pertains to the desktop
> logs. It would probably be easier to find in real-time should the
> problem happen again.

That is probably what I would do if it were me. :slight_smile:

Jim


Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C